In situ application of high temperature resistant surfactants to produce water continuous emulsions for improved crude recovery

ABSTRACT

A process for recovering oil from a subterranean hydrocarbon-bearing reservoir having a hydrocarbon and penetrated by a wellbore. The process comprises injecting through the wellbore and into the subterranean hydrocarbon-bearing reservoir an emulsifying composition containing an aqueous phase and a minor amount of an emulsifying agent such that the emulsifying composition contacts at least a portion of the hydrocarbon to form an oil-in-aqueous phase emulsion within the subterranean hydrocarbon-bearing reservoir.

This is a continuation-in-part application of copending applicationentitled "Surfactant Requirements for the Low-Shear Formation of WaterContinuous Emulsions from Heavy Crude Oil" having Ser. No. 218,840,filed July 14, 1988. The copending application having Ser. No. 218,840,filed July 14, 1988, is a continuation-in-part application of copendingapplication entitled "Preparation of Improved Stable Crude Oil TransportEmulsions" having Ser. No. 114,204, filed Oct. 27, 1987. The copendingapplication having Ser. No. 114,204, filed Oct. 27, 1987, is acontinuation-in-part application of application Ser. No. 934,683, filedNov. 24, 1986, now U.S. Pat. No. 4,725,287.

FIELD OF THE INVENTION

This invention is related to the production of oil-in-water emulsion(s).More specifically, this invention provides a process for the productionof oil-in-water emulsion(s), especially for pipeline transmission.

BACKGROUND OF THE INVENTION

The formulation of pipeline-transportable crude oil-in-water emulsioncan not generally be formulated by combining emulsifying agent(s)directly with produced hydrocarbon crude, and subsequently agitatingwith a dynamic mixer the mixture of produced hydrocarbon crude andemulsifying agent(s). The emulsifying agent(s) is not soluble in oil andis only soluble in an aqueous solution. By contacting directly theproduced hydrocarbon crude with the emulsifying agent(s) withoutpremixing the emulsifying agent(s) with water, brine, or the like,diffusion of the emulsifying agent(s) through the produced hydrocarboncrude to the oil/water interface is slow; and with some producedhydrocarbon crudes, such as Athabasca bitumen from the Athabasca tarsands in the province of Alberta, Canada, oil-in-water emulsion(s) cannot be formulated. Also, through the use of a dynamic mixer, such as therotor-stator mixer, not every produced hydrocarbon crude can beemulsified into a water continuous emulsion, even with premixing theemulsifying agent(s) with water prior to combining with producedhydrocarbon crude. A high shear field cannot be obtained with a dynamicmixer unless the mixture of produced hydrocarbon crude and emulsifyingagent(s) (including any water solvent) makes numerous passes through thedynamic mixer. Transport oil-in-water emulsion(s) is shear-sensitive,and a dynamic mixer tends to cause either an overshear-damaged productor less than a perfectly mixed product, depending on the mixing severityemployed with the dynamic mixer.

Large storage tanks and/or mixing tanks are generally required whenutilizing dynamic mixers. If a dynamic mixer is separate from thestorage tank, mixtures to be emulsified have to be recirculated from thestorage tank, through the mixer, and back into the storage tank. Thedegree of mixing achieved by dynamic mixers depends on the mixing speed,impeller design, impeller position, length of mixing time, tank volume,tank geometry, etc. Dynamic mixers are prone to producing a largequantity of oil droplets having a diameter of less than 10 micron, whichis detrimental to the transport of oil-in-water emulsion(s) as suchsmall oil droplet increase the viscosity of the oil-in-wateremulsion(s), and can cause the oil-in-water emulsion(s) to invert from awater continuous emulsion into an oil continuous emulsion, with anattendant increase in viscosity. Dynamic mixers are also susceptible tohigh maintenance expense because of their use of high-speed rotatingdevices.

What is needed and what has been invented by us is a process for thepreparation of stable water-continuous crude oil, or other hydrocarbon,transport emulsions, and which can generally form an emulsion having awater-continuous phase of any produced hydrocarbon crude, especiallyAthabasca bitumen (e.g. Syncrude bitumen) from the Athabasca tar sandsin the province of Alberta, Canada.

SUMMARY OF THE INVENTION

It is therefore an object of this invention to provide a process for thepreparation of a stable oil-in-water emulsion(s).

It is another object of this invention to provide a process for thepreparation of a stable oil-in-water emulsion(s) with the use of astatic mixer.

It is yet another object of this invention to provide a process for thepreparation of a stable oil-in-water emulsion(s) that ispipeline-transportable.

Still other objects will be apparent to those skilled in the art fromthe following description of this invention.

The foregoing objects are achieved according to the practice of thisinvention. Broadly, this invention comprises a process for theproduction of an oil-in-water emulsion that are particularly useful forpipeline transmission. The process comprises mixing a hydrocarbon withan emulsifying composition(s) which comprises water and an emulsifyingagent(s) to produce an oil-in-water emulsion when the temperature of themixture of hydrocarbon and emulsifying composition(s) is from about 100°F. to about 200° F. The amount of the emulsifying composition(s) that ismixed with the hydrocarbon is sufficient to form an oil-in-wateremulsion having a selected water content of from about 15 percent toabout 60 percent by weight water and a viscosity sufficiently low forpipeline transmission. The process additionally comprises shearing andmixing statically the mixture of hydrocarbon and emulsifyingcomposition(s) when the mixture is at a temperature of from about 100°F. to about 200° F. to form an oil-in-water emulsion.

The hydrocarbon may be any hydrocarbon or hydrocarbon crude, or anyfractionated or extracted part(s) thereof, that has a gravity of fromabout -6 degree API to about 23 degree API, preferably from about 5degree API to about 15 degree API, and with which it is desired toformulate an oil-in-water emulsion(s) for any use, especially in orderto facilitate the transmission or transportation of the hydrocarbon orhydrocarbon crude, or any fractionated or extracted part(s) thereof,through a pipeline, or the like. The hydrocarbon may be any of thosehydrocarbons that have been typically termed atmospheric bottoms, vacuumbottoms, vacuum residuals, deasphalter bottoms, etc. Thus, whenever"hydrocarbon" and/or "hydrocarbon crude" is referred to herein,"hydrocarbon" and/or "hydrocarbon crude" is to be construed to mean anyhydrocarbon or hydrocarbon crude, or any fractionated or extractedpart(s) thereof, which is capable of forming with the emulsifyingcomposition(s) of this invention, a stable oil-in-water emulsion. Theformed oil-in-water emulsion may be employed for any suitable useincluding, but not limited to, burning in a boiler (or burner),transporting through a pipeline, etc.

The emulsifying composition(s) of this invention comprises anemulsifying agent selected from the compounds having the generalformula: ##STR1## where n is from about 7 to about 20 and y is fromabout 4 to about 1000; or ##STR2## where n₁ is from about 7 to about 18,n₂ is from about 7 to about 8, and y₁ is from about 4 to about 1000. Incompound(s) (1) and/or compound(s) (2), each of y and y₁ is an integerthat represents the average number of ethylene oxide units or segmentsin the emulsifying agent(s) which is the mean of a normal Gaussiandistribution curve. The hexagon with a circle in the center incompound(s) (1) and/or compound(s) (2), and throughout thisspecification and in the claims, represents a benzene ring.

A mixture of compound(s) (1) and compound(s) (2) may be employed.Depending on the particular emulsifying agent(s), the concentration ofthe emulsifying agent(s) employed may range from about 25 to about15,000 ppm by weight of the hydrocarbon. The amount of the emulsifyingagent(s) employed is preferably just sufficient to stabilize anoil-in-water emulsion or an oil-in-aqueous phase emulsion at a 15% bywt. to about 60% by wt. water-content or aqueous phase content.

The formulated oil-in-water emulsion(s) of this invention can betransported through a pipeline. If a proportion of the disperse oildroplet phase in the oil-in-water emulsion(s) at least partiallycoalesces in the water continuous phase to produce a mixture comprisingthe coalesced oil droplet phase and residual oil-in-water emulsion, themixture may be further transported through the same pipeline, evenwithout removing the mixture for treatment or reformulation of theoriginal oil-in-water emulsion(s). It has been discovered that themixture has a viscosity less than or equal to the viscosity of theoriginally formulated oil-in-water emulsion in spite of the fact thatthe at least partially coalesced oil droplet phase has a viscositylarger than the viscosity of the originally formulated oil-in-wateremulsion(s). It has also been discovered that a substantial proportionof the originally formulated oil-in-water emulsion does not invert intoa water-in-oil emulsion when the oil droplets within the originallyformulated oil-in-water emulsion coalesce to produce a water continuousmixture comprising the coalesced oil droplets, and residual oil-in-wateremulsion which is the remaining oil-in-water emulsion from theoriginally formulated oil-in-water emulsion and contains oil dropletsthat have not coalesced.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic flow diagram of an embodiment of the process forthe preparation of stable oil-in-water emulsion(s);

FIG. 2 is a schematic flow diagram illustrating a pair of static mixingdevices in parallel;

FIG. 3 is a schematic flow diagram disclosing a pump and a static mixingdevice for producing or reproducing a multimodal oil-in-wateremulsion(s);

FIG. 4 is a partially cut-away perspective view of one embodiment of thestatic mixing device for the present invention;

FIG. 5 is a perspective view of one baffle element for the static mixingdevice of FIG. 4;

FIG. 6 is a perspective view of another baffle element for the staticmixing device of FIG. 4;

FIG. 7 a cut-away plan view of the static mixing device of FIG. 4;

FIG. 8 is a partially cut-away perspective view of another embodiment ofthe static mixing device for the present invention;

FIG. 9 is a partial perspective view of three interconnected baffleelements for the static mixing device of FIG. 8;

FIG. 10 is a partial perspective view of a baffle element for the staticmixing device of FIG. 8 with the direction of the arrows representingback-mixing action for the mixture of produced hydrocarbon crude andemulsifying composition(s);

FIG. 11 is a partial perspective view of the baffle element for thestatic mixing device of FIG. 8 with the direction of the arrowsrepresenting a splitting action for the mixture of produced hydrocarbonand emulsifying composition(s);

FIG. 12 is a partial perspective view of the baffle element for thestatic mixing device of FIG. 8 with the direction of the arrowsrepresenting cross-current mixing action for the mixture of producedhydrocarbon crude and emulsifying composition(s);

FIG. 13 is a partial perspective view of another embodiment of an end ofthe baffle element for the static mixing device of FIG. 8;

FIG. 14 is a partially cut-away perspective view of yet anotherembodiment of the static mixing device for the present invention; and

FIG. 15 is a top plan view of one of the baffle elements for the staticmixing device of FIG. 13.

FIG. 16 is an elevational view of an embodiment of an apparatus forforming a downhole oil-in-aqueous phase emulsion;

FIG. 17 is a partial enlarged elevational view of the apparatus of FIG.16;

FIG. 18 is an elevational view of an embodiment of an apparatus whichcontinuously injects an emulsifying composition downhole to form adownhole oil-in-aqueous phase emulsion;

FIG. 19 is an elevational view of an embodiment of an apparatus whichbatch injects an emulsifying composition downhole to form a downholeoil-in-aqueous phase emulsion; and

FIG. 20 is an elevational view of another embodiment of the apparatus ofFIGS. 18 and 19 for forming downhole an oil-in-aqueous phase emulsion.

DETAILED DESCRIPTION OF THE INVENTION

Referring in detail now to the drawings, and initially more particularlyto FIG. 1, a stream of hydrocarbon crude is produced from a source andis transported into a crude oil tank 10 through a conduit 12. A valve 14within the conduit 12 controls the flow of the crude through the same.The hydrocarbon crude may be any hydrocarbon and/or hydrocarbon crude,or any fractionated or extracted part(s) thereof, that preferably has agravity of from about -6 degree API to about 23 degree API.

The source of the produced hydrocarbon crude may be any source wherefroma hydrocarbon crude may be obtained, produced, or the like. The sourcemay be one or more producing wells in fluid communication with asubterranean oil reservoir. The producing well(s) may be under thermalrecovery conditions, or the producing well(s) may be in a heavy oilfield where the hydrocarbon crude or oil is being produced from areservoir having a strong water-drive. Generally, hydrocarbon crudeproduced from producing well(s) under a strong water-drive include highwater-cuts, and appropriate artificial lift systems (e.g. submersibleelectrical pumps) are employed to assist the flow of the hydrocarboncrude because of its high water content. As will be discussed in greaterdetail hereinafter, this invention is particularly suitable for when thesource of the produced hydrocarbon crude is from the Athabasca tar sandsin the province of Alberta, Canada. Hydrocarbon crude from this sourcehas generally been termed "Athabasca bitumen". No matter what the sourceis for the stream of produced hydrocarbon crude, the crude mayessentially contain no water, or it may include water in various forms.The produced crude may also include some associated gas. For thepurposes of the present invention, it will be assumed that the stream ofproduced hydrocarbon crude has a low gas/oil ratio (i.e. less than about10% by wt. of C₁ -C.sub. 5).

Any water present in the stream of produced hydrocarbon crude can beclassified into two categories: "bound" water and "free" water. "Bound"water is that water which is locked up as water-in-oil emulsion(s) thatmay be contained in the produced hydrocarbon crude. Separating "bound"water from the produced hydrocarbon crude typically requires applyingthe appropriate combination of heat, mixing and chemical additive(s)."Free" water is that water which is relatively loosely held up by theproduced hydrocarbon crude and can be removed by merely heating theproduced hydrocarbon crude to an appropriate temperature or providingsufficient residence time in tankage. The quantity of "free" water whichcan be removed will depend upon the temperature to which the stream ofproduced hydrocarbon crude is heated.

In the event that the stream of produced hydrocarbon crude contains asubstantial amount of water-in-oil emulsion(s) and/or "free" waterand/or associated gas, the crude may be fed into a "free" waterknock-out unit (FWKO) 16 through a conduit 18 that includes a valve 20to regulate and control the flow of the crude. To accomplish this changein direction of flow of the produced hydrocarbon crude, valve 20 inconduit 18 is opened, and valve 14 in conduit 12 is closed. The FWKO 16is an optional piece of equipment and is not mandatory with respect tothis invention, especially when Athabasca bitumen is being processed toformulate an oil-in-water emulsion for pipeline transportation.Athabasca bitumen contains essentially no associated gases and no waterin any form, such as "free" water and/or water-in-oil emulsion(s)wherein the contained water is "bound" water.

To accomplish the purposes of this invention, the stream of producedhydrocarbon crude may by-pass the FWKO 16, even if one produced crudecontains water-in-oil emulsion(s) and/or "free" water and/or associatedgas. The stream of produced hydrocarbon crude can contain an oil/watermixture in any proportion. in accordance with the principles of thisinvention by directly converting, changing or altering, or the like, asubstantial part of a stream of produced hydrocarbon crude ofwater-in-oil emulsion(s), with or without "free" water and with orwithout associated gases, into pipeline-transportable oil-in-wateremulsion(s). However, to facilitate the formulation of suchpipeline-transportable oil-in-water emulsion(s), there may be occasionswhere it is desirable to use the FWKO 16, such as when the producedhydrocarbon crude contains extremely high cuts of "free" water and/orassociated gases.

The FWKO 16 may be operated under pressure and has a heating unit 22 init which allows the stream of produced hydrocarbon crude to be heated toany pre-set temperature within the unit design constraints in order toassist in removal of "free" water and/or associated gas. In someinstances the stream of produced hydrocarbon crude enters the FWKO 16 ata high enough temperature so that the heating unit 22 does not have tobe energized. In the FWKO 16, depending on the temperature, a portion orsubstantially all of the "free" water will be removed from the stream ofproduced hydrocarbon crude, and can be drained and/or transmitted fromthe FWKO 16 through a conduit 24 to a water tank 26, which is also incommunication with a source of water, brine, or aqueous phase, or thelike, through a conduit 28. This water, brine, or the like, provides theaqueous phase with which the emulsifying agent(s) of this invention canbe mixed to produce the emulsifying composition(s) of this invention.Any associated gases co-produced with the produced hydrocarbon crudegenerally should separate from the stream of produced hydrocarbon crudein the FWKO 16 and vent through a conduit 30 which includes a valve 32.The separated associated gases may be transmitted for further use, orotherwise disposed.

The effluent from the FWKO 16 may be essentially a mixture ofwater-in-oil emulsion(s) and residual "free" water, if any. The effluentexits the FWKO 16 through a conduit 34 which is in communication withthe conduit 12, as illustrated in FIG. 1. Conduit 34 contains a valve 36which controls and regulates the flow of the effluent from the FWKO 16through conduit 34 and into conduit 12 where it is transported into thecrude oil tank 10. It should be re-emphasized that the stream ofproduced hydrocarbon crude may be essentially void of any of the variousforms of water and/or gases, and may not and does not have to includeany water-in-oil emulsion(s) and/or "free" water and/or associated gasfor the features of this invention to produce or formulate apipeline-transportable oil-in-water emulsion(s) by directly converting,changing, or altering the stream of produced hydrocarbon crude. Theemulsifying composition(s) of this invention in combination with otherfeatures, will generally produce pipeline-transportable oil-in-wateremulsion(s) regardless of any water-in-oil emulsion(s) and/or "free"water and/or associated gases contained within the stream of producedhydrocarbon crude.

Crude oil tank 10 has a temperature indicator 38 which monitors thetemperature of the produced hydrocarbon crude. Crude oil tank 10 alsoincludes a drain 40 which can drain off to a sump (not shown in thedrawings) extra water (if desired) which settles to the bottom of thecrude oil tank 10. When pipeline-transportable oil-in-water emulsion isto be formed in accordance with the principles of this invention, avalve 42 in a conduit 44 which is in communication with the crude oiltank 10, is opened and a crude oil pump 46 may be energized to transportproduced hydrocarbon crude through a conduit 48 for eventual mixing,commingling, adding, or the like, with the emulsifying composition(s) atthe entrance of a conduit 50. It should be understood that while themixing or adding of the produced hydrocarbon crude with the emulsifyingcomposition(s) is being represented as taking place at the entrance ofconduit 50, other systems and/or means of mixing or adding together theproduced hydrocarbon crude with the emulsifying composition(s) arewithin the spirit and scope of this invention. For example, if conduit50 is a straight line extension of conduit 48 and integral therewithsuch that conduit 48 does not have a separate identity, the emulsifyingcomposition(s) would be introduced into the conduit 48, either normal toor angular therewith. Likewise, a pump [preferably a rotating (e.g.centrifugal) pump] may be positioned in conduit 50 to further oradditionally mix the produced hydrocarbon crude with the emulsifyingcomposition(s).

As the produced hydrocarbon crude is being pumped by pump 46 through theconduit 48, it passes through a heat exchanger 52 to either heat or coolthe crude to a temperature such that when the produced hydrocarbon crudeis mixed with or added to the emulsifying composition(s), thetemperature of the crude-emulsifying composition(s) mixture is fromabout 100° F. to about 200° F., preferably from about 130° F. to about170° F., as the pipeline-transportable oil-in-water emulsion(s) is to beformed at these temperatures. It is the temperature of the mixture ofthe produced hydrocarbon crude plus emulsifying composition(s) thatshould be at a temperature of from about 100° F. to about 200° F., andnot the produced hydrocarbon crude alone. Certain produced hydrocarboncrudes, such as Athabasca bitumen from the Athabasca tar sands, may havea temperature well above 200° F. as it is being processed from the crudeoil tank 10. In those instances, and depending on the temperature of theemulsifying composition(s), the heat exchanger 52 may function as acooling unit to cool down the crude such that the crude-emulsifyingcomposition(s) mixture would possess the required temperature (i.e. fromabout 100° F. to about 200° F. as previously indicated) to formulate theoil-in-water emulsion(s). Obviously, whether the heat exchanger 52 coolsor heats the produced hydrocarbon crude would depend on the temperatureof the emulsifying composition(s).

Temperature indicator 54 monitors the temperature of the stream ofproduced hydrocarbon crude as it exits heat exchanger 52 and flowsthrough conduit 48. The rate of flow through conduit 48 is monitoredeither by a meter 56 and/or the pumping speed of pump 46. Meter 56 mayalso include a cut monitor and a sampler to monitor the composition ofthe stream of hydrocarbon crude with respect to "free" water content,water-in-oil emulsion(s), and associated gases.

The emulsifying composition(s) is formed or produced in the emulsifyingcomposition tank 58 (hereinafter referred to only as "tank 58") whichcomprises a temperature indicator 60 to monitor the temperature of theemulsifying composition(s) and a mixer means 62 to homogenize andmaintain homogenized the emulsifying composition(s). The emulsifyinqcomposition(s) of this invention comprises at least one emulsifyingagent(s); water, brine, or the like, which hereinafter will be referredto only as "water"; and, optionally, a compound that lowers the freezingpoint of water, preferably ethylene glycol, in order to lower thefreezing point of the emulsifying composition(s) and the eventuallyformed pipeline-transportable oil-in-water emulsion(s). Other compoundsthat may be employed to lower the freezing point of water include, butare not limited to, glycerol, propylene glycol, and various sugars,etc., and fall within the spirit and scope of this invention.

The emulsifying agent(s) of this invention is introduced into anemulsifying tank 64 through a conduit 66, and is dispensed into tank 58through a conduit 68. Conduit 68 includes a valve 70 and a flow-meter 72to regulate and meter, respectively, the flow of the emulsifyingagent(s) through the conduit 68. The amount of emulsifying agent(s) usedin the present invention may range from about 25 (or less) to about10,000 (or more) ppm weight-to-weight of the produced hydrocarbon crude,preferably from about 300 to about 5,000 ppm by weight. Statedalternately, the emulsifying composition(s) preferably comprises fromabout 0.05 vol. % to about 4.0 vol. % of the emulsifying agent(s).

If the produced hydrocarbon crude bypasses the FWKO 16, the actualwater-content of the produced hydrocarbon crude may vary widely. Theproduced hydrocarbon crude may contain up to about 95% by volume water,or it may be a relatively dry oil containing less than the amount ofwater required to form a low viscosity oil-in-water emulsion that ispipeline-pumpable. The object is to provide an oil-in-water emulsioncontaining from about 15% by weight to about 60% by weight water,preferably from about 25% by weight to about 35% by weight water. Toaccomplish this objective, water tank 26 is used to furnish water totank 58. This water may be recovered from the as-received stream ofproduced hydrocarbon crude by separation in FWKO 16 (which is optional),or may be water externally derived from a source which is introducedinto water tank 26 through conduit 28. The amount of emulsifyingagent(s) added from emulsifier tank 64 is controlled so as to form agenerally stable oil-in-water emulsion with an emulsifying agent(s)concentration suited for low-viscosity pipeline pumping. Any extra waterwill be loosely bound and should separate easily. Excess emulsifyingagent(s) is expensive and should be avoided. The introduction of toolittle emulsifying agent(s) is to be also avoided because anoil-in-water emulsion will not form suitable for pipelinetransportation. However, the employment of too little emulsifieragent(s), or not enough emulsifier agent(s) for transportation through along pipeline (such as over 1,000 miles long), is not critical becauseone of the features of this invention is that although the formulatedoil-in-water emulsion may fail and/or breakdown in a pipeline into amixture comprising an at least partially (i.e. partially orsubstantially) coalesced oil droplet phase and residual oil-in-wateremulsion, the resulting mixture has a viscosity that is less than orequal to the viscosity of the original oil-in-water emulsion(s)notwithstanding the fact that the at least partially coalesced oildroplet phase itself has a viscosity larger than the viscosity of theoriginal oil-in-water emulsion(s). An attendant feature to this featureof the invention is that if and when the oil-in-water emulsion(s) ofthis invention fails or breaksdown in a pipeline into the mixturecomprising an at least partially coalesced oil droplets and residualoil-in-water emulsion(s), it is done so without a substantial proportionof the formulated oil-in-water emulsion(s) being inverted into awater-in-oil emulsion. These features enable the mixture of coalescedoil droplets and residual oil-in-water emulsion to be continuouslytransported through the pipeline without having to remove the mixture toreformulate the oil-in-water emulsion(s).

A conduit 74 transports water from the water tank 26 into the tank 58wherein water and the emulsifying agent(s) are mixed or combinedtogether into the emulsifying composition(s). The pH of the emulsifyingcomposition(s) in tank 58 may be modified by chemical addition. A filter(not shown in the drawings) may be installed in conduit 74 to removesediment. A valve 76 and a flow meter 78 are in conduit 74 to controland meter, respectively, the flow of the water. It is important that theemulsifying agent(s) of this invention be mixed or combined with watersuch that the emulsifying composition(s) contain water. If water isabsent from the emulsifying composition(s), and the emulsifying agent(s)in a pure or relatively pure state contacts and/or mixes with theproduced hydrocarbon crude, a pipeline-transportable oil-in-wateremulsion(s) cannot be produced or formulated, even if water is addedseparately to the produced hydrocarbon crude, or the crude containswater in any of its various forms. The emulsifying agent(s) of thisinvention is essentially insoluble in hydrocarbon crude and would notform a homogeneous solution with the hydrocarbon crude. Also, unlesswater is present with the emulsifying agent(s) of this invention,diffusion of the emulsifying agent(s) through the hydrocarbon crude tothe interface of the crude and water (which was separately added oralready contained within the crude) is much too slow, if it occurs atall. This is especially true for Athabasca bitumen. Therefore, one ofthe salient features of this invention is the mixing of the emulsifyingagent(s) with water prior to any emulsifying agent(s) contacting theproduced hydrocarbon crude.

As was previously mentioned, a suitable freezing point depressant may bemixed with the water to lower the freezing point of the water and/or theemulsifying composition(s) and/or the eventually formed oil-in-wateremulsions(s). For the purposes of illustrating this invention, ethyleneglycol will be employed as the freezing point depressant. To accomplishthe mixing of water with ethylene glycol, conduit 82 supplies anethylene glycol tank 80 with ethylene glycol. Ethylene glycol can beintroduced directly into the water tank 26 through a conduit 84 thatcontains a valve 86 for regulating the flow of ethylene glycoltherethrough. A flow meter 88 is also provided within conduit 84 tomonitor the direct flow of ethylene glycol into the water tank 26.Alternatively, ethylene glycol can be introduced directly through aconduit 90 into water that is flowing within conduit 74 from the watertank 26. Similarly to conduit 84, conduit 90 is provided with a valve 92and a flow meter 93 to regulate and meter, respectively, the flow ofethylene glycol through conduit 90. To effect the flow of ethyleneglycol through conduit 84, valve 86 in conduit 84 is opened and valve 92in conduit 90 is closed; and to effect the flow of ethylene glycolthrough conduit 90, valve 92 in conduit 90 is opened and valve 86 inconduit 84 is closed. Optionally, to accomplish the purpose for usingethylene glycol, instead of introducing and mixing directly the ethyleneglycol with the water, ethylene glycol may be introduced into and mixeddirectly with the emulsifying agent(s), or with the mixture of water andemulsifying agent(s) within the tank 58.

The emulsifying composition(s) of this invention is pumped out of tank58 through a conduit 94 by an emulsifying composition pump 96. Beforecommencing the pumping of the emulsifying composition(s) through theconduit 94 with the pump 96, valve 98 at the bottom of the tank 58 andwithin the conduit 94 is opened. Emulsifier composition pump 96 furtherpumps or transports the emulsifying composition(s) through a conduit 100to meet with, combine or mix with, or the like, the stream of producedhydrocarbon crude at the entrance of the conduit 50. Conduit 100 isprovided with a flow meter 102 to monitor and indicate the flow of theemulsifying composition(s) en route to its meeting with the producedhydrocarbon crude. Conduit 100 passes through a heat exchanger 104 whichis provided in order to control and provide the emulsifyingcomposition(s) with a sufficient temperature such that when it meets andmixes with the produced hydrocarbon crude at the entrance to conduit 50,the temperature of the mixture of emulsifying composition(s) andproduced hydrocarbon crude within conduit 50 is from about 100° F. toabout 200° F. As was previously indicated, maintaining the temperatureof the mixture of emulsifying composition(s) and produced hydrocarboncrude from about 100° F. to about 200° F. is important in order to formthe oil-in-water emulsion(s), as well as to produce and/or maintain aviscosity of the mixture that enables the mixture to be pumped ortransported through a pipeline. This is especially true when theproduced hydrocarbon crude is Athabasca bitumen which may at timespossess a temperature above 200° F. and/or a high viscosity (e.g. 20,000cp at about 100° F.) that would render it difficult to pump or transportthrough a pipeline. Thus, heat exchanger 104, depending on thetemperature of the produced hydrocarbon crude at the temperatureindicator 54 and/or the temperature of emulsifying composition(s) fromtank 58, may at times have to heat the emulsifying composition(s); atother times may have to cool the emulsifier composition(s) instead ofheating it, in order that the mixture of produced hydrocarbon crude andemulsifying composition(s) possesses the appropriate temperature of fromabout 100° F. to about 200° F.; more preferably from about 160° F. toabout 195° F. when the produced hydrocarbon crude is Athabasca bitumenbecause of the high viscosity factor of the Athabasca bitumen.

The pressure drop across the mixer is monitored as it travels throughconduit 50 by a pressure and flow meter monitor 106. Conduit 50 leads orterminates into a static shearing and static mixing means or device,generally illustrated as 108, which produces the oil-in-wateremulsion(s) when the mixture is passed at a certain velocitytherethrough and at the temperature of from about 100° F. to about 200°F. In a preferred embodiment of the invention, the device 108 is notpreceded or followed by any dynamic shearing and mixing device (such asin-line blenders, rotor-stator, homogenizer, etc.) because the qualityof the produced oil-in-water emulsion(s) may be affected if shearedand/or mixed dynamically, especially for certain species of emulsifieragent(s) which will be more fully set forth hereinafter. With respect tothese certain species of emulsifier agent(s) when used to formulateoil-in-water emulsion(s) with dynamic mixing and/or dynamic shearing,such formulated oil-in-water emulsions(s) tend to fail and/or breakdowninto the previously indicated mixture comprising an at least partially(i.e. partially or substantially) coalesced oil droplets in the watercontinuous phase, and residual oil-in-water emulsion. As was previouslymentioned, not withstanding such failure and/or breakdown, the resultingcoalesced oil droplets-residual emulsion mixture would still have aviscosity less than or equal to the original oil-in-water emulsion(s).Therefore, such mixture may be continually transported or pumped througha pipeline, or the like, without any concerns for non-effectivepipeline-viscosity that may have resulted from the failure and/orbreakdown due to dynamic shearing and/or dynamic mixing. Theeffectiveness of other species of the emulsifier agent(s) of thisinvention is not affected by any form or means of agitation, includingbut not limited to dynamic shearing and/or dynamic mixing. Thus, whilestatic shearing and/or static mixing may be a preferred means forformulating the oil-in-water emulsion(s) of this invention, dynamicshearing and/or dynamic mixing is within the spirit and scope of thisinvention for certain embodiments thereof.

The velocity of the mixture of produced hydrocarbon crude andemulsifying composition(s) through the static shearing and static mixingdevice 108 may be any suitable velocity as the oil-in-water emulsion(s)of the present invention may be formed or produced under laminar orturbulent flow conditions. However, in a preferred embodiment of thepresent invention, crude oil pump 46 and emulsification composition pump96 should be fixed or set such that when the mixture of emulsifyingcomposition(s) and produced hydrocarbon crude enters the static shearingand static mixing device 108, the velocity of the mixture is from about20 in./sec. to about 140 in./sec., more preferably from about 35in./sec., to about 115 in./sec. The viscosity of the mixture may be anyviscosity that enables the mixture to be pumped, but is preferably fromabout 100 cp. to about 10,000 cp. At a velocity ranging from about 20in./sec. to about 140 in./sec., and depending on the viscosity of themixture, the pressure drop across the mixture within conduit 50 is fromabout 10 psi. to about 150 psi., preferably from about 20 psi. to about60 psi.

The static shearing and static mixing device 108 simultaneously shearsand mixes the mixture of emulsifying composition(s) and the producedhydrocarbon crude together when the mixture is at the temperature offrom about 100° F. to about 200° F. to form the pipeline-transportableoil-in-water emulsion(s), and is also one of the salient features ofthis invention. The objective of this device 108 is to coalesce most orall of the water present, including any water that might be present inthe produced hydrocarbon crude as water-in-oil emulsion and/or as "free"water, into one continuous phase, and simultaneously disperse all theoil in the form of small droplets in this continuous water phase. Water,if any, present in the produced hydrocarbon crude in the form ofwater-in-oil emulsion and/or "free" water is converted, changed, oraltered in the device 108 into oil-in-water emulsion(s). The degree ofconversion or alteration sought is 100%. In order to avoid production ofan inverted-phase emulsion (i.e. an oil continuous emulsion), theemulsion composition(s) is preferably initially passed through thedevice 108 in a relatively pure state (i.e. not combined or mixed withthe produced hydrocarbon crude) before being combined or admixed withthe produced hydrocarbon crude at the entrance of conduit 50 in order towet the mixer internals of the device 108 with the desired watercontinuous phase. As will be discussed below in greater detail, thedevice 108 has various embodiments (as illustrated in FIGS. 4-14) andmay be employed singly (see FIG. 3), or in parallel (see FIG. 2), toproduce multimodal oil-in-water emulsion(s) having a lower viscositythan the viscosity of a unimodal oil-in-water emulsion(s). The staticshearing and static mixing device 108 is preferably cylindrical with anysuitable diameter, such as from about 0.2 inches to about 6.0 feet.

The effluent of the static shearing and static mixing device 108 isdischarged into a conduit 110 and is substantially a water-external,oil-in-water emulsion(s) that is suitable for pipeline transportation.However, this oil-in-water emulsion(s) may contain extra water relativeto that required to achieve a certain pipeline viscosity. A sampler 112is provided within conduit 110 such that the oil-in-water emulsion(s)leaving the static shearing and static mixing device 108 passes throughthe sampler 112 whereby the quality of oil-in-water emulsion(s) achieved(including any water-in-oil emulsion(s) that might have been initiallycontained within the produced hydrocarbon crude and subsequentlyconverted or changed in the static shearing and static mixing device 108into the oil-in-water emulsion(s)) can be checked and determined.Conduit 110 also includes a valve 113 for regulating or terminating theflow of oil-in-water emulsion(s) therethrough.

If needed, and optionally, the formulated oil-in-water emulsion(s) canbe recycled through a line 114, using a recycle pump 99, and back to thepoint of where the mixture of emulsifying composition(s) and producedhydrocarbon crude is introduced into the static shearing and staticmixing device 108 to ensure formation of proper oil-in-wateremulsion(s). To accomplish this recycle operation, recycle pump 99 isenergized after valve 113 in conduit 110 is closed and a valve 115(which is normally closed) in conduit 114 is opened. A temperatureindicator 116 is provided in conduit 110 to monitor the temperature ofthe oil-in-water emulsion(s) flowing therethrough. Optionally, degassingboot 118 may also be provided in conduit 110 if degassing of theoil-in-water emulsion(s) is desired or needed. After the degassing boot118, the pipeline-transportable oil-in-water emulsion(s) flows through aheat exchanger 120 and into an emulsion tank 122, or directly to apipeline 123. The objective of the heat exchanger 120 is to provide anoption for cooling the oil-in-water emulsion(s) flowing through conduit110 to a temperature below about 120° F., preferably below about 100°F., more preferably from about 80° F. to about 100° F. Some oil-in-wateremulsion(s) of this invention are temperature sensitive. At hightemperatures (i.e. above about 120° F.) these oil-in-water emulsion(s)may have reduced stability. In order to achieve a more stableoil-in-water emulsion(s), the temperature of the oil-in-wateremulsion(s) flowing through the conduit 110 should be lowered belowabout 120° F. At temperatures below about 120° F., the stability of theoil-in-water emulsion(s) of this invention increases.

In the emulsion tank 122, the pipeline-transportable oil-in-wateremulsion(s) is ready to be transmitted or transported through a conduit124 to the pipeline 123. The quality of the oil-in-water emulsion(s) maybe checked by another meter 126 having a cut monitor and sampler and, ifsatisfactory, it is sent to the pipeline 123 for transportation to adesired destination.

It should be noted that as long as the temperature of the oil-in-wateremulsion(s) within the emulsion tank 122 is below about 120° F., thereshould be no problems with the oil-in-water emulsion(s) with respect tostability. Similarly, as long as the quantity of water in the effluentoil-in-water emulsion(s) is greater than what is needed, there should beno problems with the oil-in-water emulsion(s) with respect topipeline-viscosity standpoint, especially for Athabasca bitumen. Excesswater in the oil-in-water emulsion(s) is of no major concern when theoil-in-water emulsion(s) is to be transported through a pipeline that isnot too long, such as one (1) to two (2) miles. However, excess waterfor a long pipeline should not be too large because there may belimitations in the pipeline from a pumping-capacity standpoint. Therecould be a problem, especially when the produced hydrocarbon crude isAthabasca bitumen, if the amount of water in the effluent oil-in-wateremulsion(s) is less than what is required from an effectivepipeline-viscosity standpoint. Once the amount of water in theformulated oil-in-water emulsion(s) is the appropriate amount for aneffective pipeline-viscosity, the formulated oil-in-water emulsion(s)may be pumped or transported through a pipeline of any length (such asover 1,000 miles) without any fears or concerns about the formulatedoil-in-water emulsion(s) failing and/or breaking down into a mixture orphases that do not possess an effective viscosity for pipelinetransportation. As was previously indicated, a salient feature of theoil-in-water emulsion(s) of this invention is that although theformulated oil-in-water emulsion may fail and/or break down in apipeline into a mixture comprising an at least partially (i.e. partiallyor substantially) coalesced oil droplets in the water continuous phaseand residual oil-in-water emulsion(s), the mixture has a viscosity thatis less than or equal to the viscosity of the original oil-in-wateremulsion(s) in spite of the fact that the coalesced oil droplet phaseitself has a viscosity larger than the viscosity of the originaloil-in-water emulsion(s). It should be understood that the mixture mayinclude some (but not a substantial amount) formed oil-in-water emulsionthat has inverted into a water-in-oil emulsion. Such water-in-oilemulsion may be part of the coalesced oil droplet phase and/or theresidual oil-in-water emulsion and/or separate from both the coalescedoil droplet phase and the residual oil-in-water emulsion. With theemulsifier agent(s) of this invention in combination with other featuresof this invention, when the oil-in-water emulsion(s) fail or breakdownin a pipeline into the mixture comprising at least partially coalescedoil droplets and a residual oil-in-water emulsion(s), a substantialproportion of the original, formulated oil-in-water emulsion(s) is notinverted into a water-in-oil emulsion. The residual oil-in-wateremulsion(s) may be defined as the remaining oil-in-water emulsion(s)from the original oil-in-water emulsion(s) whose contained dispersed oildroplets have not at least partially coalesced. These features of thepresent invention enable the mixture comprising the at least partiallycoalesced oil droplets and residual oil-in-water emulsion to becontinuously pumped or otherwise transported through the same pipeline(i.e. pipeline 123) that the original oil-in-water emulsion(s) wasintroduced into, without the need for removing the mixture toreformulate the oil-in-water emulsion(s). However, one of the desirablequalities of the oil-in-water emulsion(s) of this invention is that ifthere is a breakdown or failure in the original oil-in-water emulsion(s)into the coalesced oil droplet-residual emulsion mixture, the originaloil-in-water emulsion(s) may be easily reformulated by merely passingthe mixture through another device 108 which may be situated within thepipeline that is transporting the oil-in-water emulsion(s) or off to theside of the pipeline in a bypass loop, as illustrated in FIG. 3. Thus,if desired, such reformulation may be easily accomplished even though itis not necessary to do so to continue the pumping or transportation ofthe failed or broken down original oil-in-water emulsion(s).

The emulsifying agent(s) of this invention used in the preparation ofthe oil-in-water emulsions may gradually become inactivated duringpipeline flow, depending on the original concentration or quantity ofemulsifying agent(s) employed, the temperature of the emulsion-formingconstituents (i.e. crude and emulsifying composition) at formulation,etc. Regardless of any formulation condition, the formed oil-in-wateremulsion will eventually separate into the two-phase mixture (i.e. thecoalesced oil droplet-residual emulsion mixture) which, as was indicatedabove, will continue to flow under ordinary circumstances. The totaldistance through a pipeline in which an oil-in-water emulsion may bepumped or otherwise transported prior to separation into the two-phasemixture also depends on the original concentration or quantity of theemulsifying agent(s) employed, and the temperature of the emulsionforming constituents at formulation, as well as other properties of thehydrocarbon crude oil and aqueous phase (i.e. water, brine, or thelike), and pipeline and pumping conditions. If, for any reason, theoil-in-water emulsion can not be prepared with sufficient stability tobe pumped (or otherwise transported) over the total length of apipeline, another embodiment of the present invention provides forremedial procedures to restore the oil-in-water emulsion in order toallow for the continued transportation of the formed oil-in-wateremulsion through a pipeline for any desired distance. More specifically,it has been discovered that through the addition of additional aqueousphase and/or the addition of additional concentrated emulsifyingcomposition [or additional pure emulsifying agent(s)] into the pipelinethat has been transporting the original formed oil-in-water emulsionthat has separated into the two-phase mixture (or the coalesced oildroplet-residual emulsion mixture), the separated oil-in-water emulsioncan be restored into the original formed oil-in-water emulsion withsufficient agitation, such as by pumping or the like. The selection ofadditional aqueous phase and/or additional concentrated emulsifyingcomposition [or pure emulsifying agent(s)] depends on the condition orstate of the separated oil-in-water emulsion, the pipeline and pumpingconditions, the desires of the pipeline operator and refiner or otherreceiver of the oil-in-water emulsion, and etc. Depending further on thepipeline and pumping conditions, it has been discovered that should eventhe original formed oil-in-water emulsion completely fail or otherwisetransform into a highly viscous oil continuous system, such oilcontinuous system can be restored into the original formed oil-in-wateremulsion through the addition or injection into the pipeline ofadditional emulsifying composition along with agitation, such as pumpingor shearing and mixing statically. The use of this technique to correcta total oil-in-water emulsion failure would require that the necessaryquantities of emulsifying composition be available and injection pumpsbe located at the location in the pipeline where the total failure hasoccurred.

The addition of additional aqueous phase into the pipeline transportingor carrying the separated oil-in-water emulsion allows the separatedoil-in-water emulsion to be transported even if the separated emulsionshould show a tendency to inversion or total failure into an oilcontinuous system. The amount of additional aqueous phase requireddepends on the properties of the crude, but is typically of an amountsufficient to increase or maintain the total aqueous phase concentrationin a given volume of oil-in-aqueous phase emulsion in a range of fromabout 40% to about 60% (preferably 45% to 55%) volume percent. Theutilization of the additional aqueous phase technique requires that theadditional quantities of aqueous phase and injection pumps be availablefor use when and at the pipeline location where the originally formedoil-in-water emulsion separates into the emulsion mixture comprising thecoalesced oil droplet phase and the residual oil-in-water emulsionphase. The amount of additional aqueous phase to be added must also beconsidered in relation to receiving tankage and treatment equipment atthe pipeline termination.

The addition of additional concentrated emulsifying compositions [oradditional pure emulsifying agent(s)] either alone or in combinationwith additional aqueous phase has some advantages over the employment ofaqueous phase alone. A concentrated emulsifying composition may bedefined as that amount of emulsifying composition that is necessary orequivalent for raising or maintaining the emulsifying agent(s)concentration of from about 250 ppm to 1500 ppm or higher of emulsifyingagent(s) by weight of hydrocarbon oil/crude, after the emulsifyingcomposition is added or injected into the separated oil-in-wateremulsion. This procedure results in a lower emulsion mixture viscosityand a smaller increase in the total volume of the oil-in-water emulsion.Additional concentrated emulsifying composition [or additional pureemulsifying agent(s)] either alone or in combination with additionalaqueous phase should be added or injected into the pipeline before orsoon after separation and before any substantial portion of the aqueousphase is absorbed into the hydrocarbon oil/crude phase.

The additional concentrated emulsifying composition [or additional pureemulsifying agent(s)] either alone or in combination with additionalaqueous phase may be used on a routine basis to reduce the totalquantity of emulsifying agent(s) initially employed or required byhaving one or more intermediate emulsifier injection points along thepipeline transporting the oil-in-water emulsion in order to periodicallyinject the additional concentrated emulsifying composition [oradditional pure emulsifying agent(s)], either alone or in combinationwith additional aqueous phase. If all of the required emulsifyingagent(s) are employed initially at the beginning of the pipeline, excessemulsifying agent(s) is required to provide the necessary safety marginneeded to ensure that separation or total failure does not occur. By theuse of one or more intermediate emulsifier injection points along thepipeline transporting the oil-in-water emulsion, the total quantity ofemulsifying agent(s) to be used can be optimized such that there is noexcess or waste of emulsifying agent(s) at any point along the pipeline.Thus, the total quantity of emulsifying agent(s) used along the entirelength of the pipeline would be less than the quantity of emulsifyingagent(s) used for a sole injection only at the beginning of thepipeline.

It should also be pointed out that solid pellets of pure emulsifyingagent(s) may be placed or injected periodically into the pipeline(either at the beginning or at intermediate positions) carrying ortransporting oil-in-water emulsion in order to maintain the oil-in-wateremulsion in an emulsion state while preventing separation or totalfailure. The solid pellets of pure emulsifying agent(s) injectionprocedure is thus another means of optimizing the quantity ofemulsifying agent(s) used because the solid pellets would constantly,gradually emit, put forth, or dissolve fine solid quantities of pureemulsifying agent(s) into the stream of oil-in-water emulsion as thesolid pellets travel through the pipeline along with the oil-in-wateremulsion, allowing the initial quantity of emulsifying agent(s) used toform the oil-in-water emulsion to be smaller or less than the quantitythat would have to be used if the solid pellets were not employed.Therefore, another embodiment of the present invention provides for amethod for restoring the properties of a water continuous emulsion witha hydrocarbon crude after the emulsion has experienced phase separationin a pipeline comprising either or a combination of the following steps:(1) adding on a continuous basis at one or more points along thepipeline additional aqueous phase to the flowing separated emulsion toincrease the total water concentration from 40% to 60% by volume; (2)adding on a continuous basis at one or more points along the pipelineadditional emulsifying composition (or emulsifying agent(s) which may bein solid pellet or particulate form) to the flowing separated emulsionto increase the stability of the oil-in-water emulsion in order that itmay be pumped to the end of the pipeline without total failure orinversion into an oil continuous phase. The present invention furtherprovides for a method for reducing the total quantity of emulsifyingagent(s) necessary for pipeline transportation of a heavy crude orbitumen water continuous emulsion and simultaneously reducing the riskof emulsion separation comprising the following steps: (1) preparing anoil-in-water emulsion with a smaller quantity of emulsifying agent(s)necessary for transporting the formed oil-in-water emulsion over theentire length of the pipeline; (2) injecting at one or more points alongthe pipeline additional emulsifying compositions (or emulsifyingagent(s) which may be in solid pellet or particulate form) in order tominimize and optimize the total quantity of emulsifying agent(s)required. The solid form of the emulsifying agent(s) may be placed inthe formed oil-in-water emulsion at the beginning of the pipeline toflow with the flowing emulsion to gradually dispose of additionalemulsifying agent(s) in the emulsion while flowing through the length ofthe pipeline.

After the oil-in-water emulsion(s) has been transported or pumpedthrough the pipeline 123 to its final destination, the oil droplets areseparated from the oil-in-water emulsion(s) in a separating station 300that is positioned at the end of the pipeline 123. The separated oilleaves the separating station through pipeline 302 and the residualwater product after the oil has been separated, which is water plus anyadditives (e.g. ethylene glycol, etc.), should be recycled back to thewater tank 26, or the tank 58, through conduit 304 admixed with theproduced hydrocarbon crude. Separating the oil droplets from theoil-in-water emulsion(s) may be accomplished by any suitable means, suchas heating the oil-in-water emulsion(s) above the phase inversiontemperature (P.I.T.), which is generally from about 180° F. to about210° F., and/or adding deemulsifier(s). Any deemulsifier(s) added to theoil-in-water emulsion(s) and contained within the residual water productafter the oil has been separated has little or no effect on theemulsifying agent(s) of this invention.

In another embodiment of the present invention, the formed oil-in-wateremulsion is broken, destroyed, dissipated, or any of the like(hereinafter referred to as ¢breaking the oil-in-water emulsion") inorder to recover the oil phase while simultaneously destroying anyundesirable components resulting from degradation and/or reduction ofthe emulsifying agent(s) while in transit. Such undesirable componentsas phenols and other phenolic structure compounds may result from theemulsifying agent(s) of this invention degrading or being reduced whilethe formed oil-in-water emulsion is being transported through thepipeline. Thus, it becomes desirable to remove these undesirablecomponents which are generally water soluble. It becomes even moredesirable to remove these undesirable components while simultaneouslybreaking the formed oil-in-water emulsion. In the present invention,such undesirable phenol components are removed while simultaneouslybreaking the formed oil-in-water emulsion through the use of potassiumpermanganate, preferably employed in a quantity or concentration of fromabout 500 ppm to about 15,000 ppm (more preferably 1000 to 2000 ppm) ofpotassium permanganate by weight of oil-in-water emulsion. Potassiumpermanganate breaks up the formed water continuous emulsion andsimultaneously destroys any undesirable phenols in a single-stepoperation.

Potassium permanganate is a powerful oxidizing chemical which destroysphenolic compounds and other undesirable compounds containing benzene byattacking the double bonds. Potassium permanganate also reacts and/orbreaks the --CH₂ --CH₂ --O--_(y) repeat segments or units in theemulsifying agent(s) to break the water continuous emulsion. During theattack and/or reaction, water and manganese dioxide and carbon dioxideform, along with by-products. When potassium permanganate is utilized inremoving phenol in a holding tank, the phenol is oxidized rapidly at apH of 7.0 to 11.0, preferably 8.5 to 9.5. A retention time of fromfifteen minutes to about six hours in a reactor and/or a retention timeof fifteen minutes to two weeks in a tankage, is sufficient to insurecomplete oxidation of the phenol. The initial reaction takes placealmost immediately, and almost 90% of the phenol is generally oxidizedin the first ten minutes. Other suitable oxidizers for phenol treatmentand breaking the water continuous emulsions are ozone (O₃, hydrogenperoxide (H₂ O₂), and chlorine (Cl₂). These oxidizers are typicallyemployed in any suitable manner (e.g. chlorination, ozonation, etc.) inquantities ranging from 500 ppm to 15,000 ppm of oxidizer by weight ofoil-in-water emulsion.

A preferred procedure for treating the oil-in-water emulsion withpotassium permanganate is to mix (either statically or dynamicallyand/or in a reactor) the water continuous emulsion with a diluted streamof potassium permanganate (i.e. a potassium permanganate-aqueous mixturehaving 85 wt. % to 99 wt. % of the aqueous phase). The potassiumpermanganate preferentially reacts with the emulsifying agent(s) asopposed to constituents in the hydrocarbon oil/crude. After thoroughmixing, the mixture is preferably discharged into a conventional vesselfor a quiescent period ranging from about fifteen minutes to about twoweeks. Typically, during the quiescent period, the hydrocarbon oil/crudecoagulates and rises to the top while the aqueous phase settles to thebottom. The hydrocarbon oil/crude is removed off of the aqueous phase aseffluent and is fed into a desalter where separation of the mixtureoccurs into waste water and hydrocarbon oil/crude for refining purposes.The waste water may have to be further treated with an oxidizer (e.g.dilute KM_(n) O₄, ozone, chlorine, etc.) and a mixer (e.g. static mixer,high shear pump, etc.) in accordance with the procedure as previouslyset forth for treating water continuous emulsions for phenols whilesimultaneously breaking the emulsion.

Alternatively to separating the oil droplets from the oil-in-wateremulsion(s) or breaking the oil-in-water emulsions, the existingoil-in-water emulsion(s) can be used in its existing state, such as forfuel, and there would be no need to separate the oil droplets from theexisting oil-in-water emulsion. Thus, in those instances where theoil-in-water emulsion(s) is to be burned as fuel, the oil-in-wateremulsion(s) can be fed directly to a boiler (e.g. utility boiler,fluidized bed boiler, etc.). No separation step would have to beemployed unless the BTU content of the oil-in-water emulsion(s) is toolow.

The emulsifying agent(s) of this invention may be any emulsifying agentwhich, when combined with an appropriate amount of water, is capable offorming in the produced hydrocarbon crude an oil-in-water emulsion whenthe temperature of the crude-emulsifying agent mixture is from about100° F. to about 200° F. Generally, unless a broad-based emulsifyingagent is used, a mixture of at least two emulsifying agents is employed.Surface-active agents used to form oil-in-water emulsion(s) may be andpreferred characteristic is a high degree of oil insolubility. in oil.Most of the inexpensive and efficient candidates for forming crudeoil-in-water emulsion(s) are either anionic or nonionic. Nonionics arepresently preferred because they are generally cheaper and not affectedby the salinity of the water.

The best known of all the anionic-active emulsifying agents are thesoaps which are the salts of the long-chain fatty acids, derived fromnaturally occurring fats and oils, in which the acids are found astriglycerides. The soaps used as emulsifying agents may be obtained fromnatural oils, in which case they will consist of a mixture of fattyacids, the precise nature of the mixture depending on the fat or oilemployed. The mixed fatty acids of tallow, coconut oil, palm oil, andthe like, are those commonly employed. The acids derived from tallow,for instance, may be partially separated by filtration or by pressinginto "red oil" (principally oleic acid) and the so-called "stearic acid"of commerce, which is sold as single-, double-, or triple-pressed,depending on the extent to which oleic acid is separated. Such stearicacid is actually a mixture of stearic and palmitic acids.

The nonionic emulsifying agents can be classified into five types,namely, ether linkage, ester linkage, amide linkage, miscellaneouslinkages, and multiple linkage. Preferred nonionic emulsifying agent(s)are substantially oil insoluble and are those selected from thecompounds having the general formula: ##STR3## where each of R, R₁ andR₂ is any hydrocarbon group, preferably alkyl radical containing fromabout 8 to about 21 carbon atoms, and each of y and y₁ is an integerthat represents the average number of ethylene oxide units or segmentsin the emulsifying agent(s), which is the mean of a normal Gaussiandistribution curve. Preferably, each of y and y₁ ranges from about 4 toabout 100, more preferably from about 30 to about 100. Most preferably,each of R, R₁ and R₂ is C₉ H₁₉, and each of y and y₁ is 40 or 100. Whenthe oil-in-water emulsion(s) of this invention are formulated with thenonionic emulsifying agent(s) represented by the general formula (1)and/or the general formula (2), the static shearing and static mixingdevice 108 is preferably employed without being preceded or followed byany dynamic shearing and mixing device, because it has been discoveredthat the longevity quality of the formulated oil-in-water emulsion(s) isaffected if produced through the use of a dynamic shearing and/or mixingdevice. However, even if nonionic emulsifying agent(s) represented bythe general formula (1) and/or the general formula (2) is employed alongwith dynamic shearing and/or dynamic mixing, and the formulatedoil-in-water emulsion(s) fails and/or breaksdown while being transportedthrough a pipeline, it has been discovered that the viscosity of thefailed and/or brokendown mixture, which comprises coalesced andseparated oil droplets in the water continuous phase and residualoil-in-water emulsion, is less than or equal to the original formulatedoil-in-water emulsion(s). It has been discovered that this is true eventhough the viscosity of coalesced and separated oil droplets is morethan the original formulated oil-in-water emulsion(s). Thus, the failedand/or brokendown mixture may be continually pumped through the pipelinewithout any concerns for non-effective pipeline-viscosity.

Other preferred nonionic emulsifying agent(s), especially when theproduced hydrocarbon crude is Athabasca bitumen, are those selected fromthe compounds which are substantially oil insoluble and have the generalformula: ##STR4## where n is from about 7 to about 20, preferably 11,and y is an integer that represents the average number of ethylene oxideunits or segments in the emulsifying agent(s), which is the means of anormal Gaussian distribution curve and is from about 101 to about 250,preferably from about 120 to about 180, more preferably about 150; and##STR5## wherein n₁ is from about 7 to about 18, preferably about 8, n₂is from about 7 to about 18, preferably about 8, and y₁ is an integerthat represents the average number of ethylene oxide units or segmentsin the emulsifying agent(s), which is the mean of a normal Gaussiandistribution curve and is from about 101 to about 250, preferably fromabout 120 to 180, more preferably about 150.

Preferably, the nonionic emulsifying agent(s) of this invention is acombination of the compounds having the general formula (3) and thecompounds having general formula (4), with the compounds having thegeneral formula (4) being at least 40% by weight of the combination.More preferably, the compounds having general formula (4) are from about50% by wt. to about 85% by wt of the combination.

The most prominent members of the class of nonionic emulsifying agent(s)represented by the foregoing general formulas (1), (2), (3) and (4) arethose compounds formed by the reaction of a hydrophobichydroxyl-containing compound, e.g., an alcohol or phenol, with ethyleneoxide. The ethylene oxide groups, for example, may be added to anydesired extent.

The emulsifying composition(s) of this invention can compriseemulsifying agent(s) represented by the general formula (1) and/or thegeneral formula (2) in combination with the emulsifying agent(s)represented by the general formula (3) and/or the general formula (4).Typically, when such combination or combinations are employed, theamount or quantity of emulsifying agent(s) represented by the generalformula (3) and/or the general formula (4) would comprise from about 20%by wt. to about 80% by wt. of the total amount or quantity of theemulsifying agent(s) employed within the emulsifying composition(s).

It has been discovered that when the oil-in-water emulsion(s) of thisinvention are produced or formulated with the nonionic emulsifyingagent(s) represented by the general formula (3) and/or the generalformula (4), any form or means of agitation may be utilized for suchproduction or formulation. Any dynamic shearer or mixer may be utilized,as well as the preferred static shearing and static mixing device 108.

Should a portion of the oil droplets in the oil-in-water emulsion(s)formulated with the nonionic emulsifying agent(s) represented by any ofthe general formulas (1)-(4), either taken singly or in combination,partially coalesce for any reason to form partially coalesced oil, themixture comprising the oil-in-water emulsion including the partiallycoalesced oil may be continually transported or pumped through apipeline for the same reasons that have been previously stated. Toreiterate and to be more specific, the viscosity of the oil-in-wateremulsion containing partially coalesced oil has a viscosity lower thanor equal to the original oil-in-water emulsion(s) in spite of the factthat the viscosity of the partially coalesced oil droplets is largerthan the viscosity of the originally formulated oil-in-wateremulsion(s). Thus, the failed and/or brokendown mixture may even have aviscosity that makes it more favorable for pipeline transportation thanthe originally formulated oil-in-water emulsion(s).

The presently nonionic emulsifying agent(s) having an ester linkageinclude compounds of the following general formula: ##STR6## where R isany hydrocarbon group, preferably an alkyl radical containing from about8 to about 21 carbon atoms, more preferably R is C₉ H₁₁₉ ; and y is aninteger that represents the average number of ethylene oxide units orsegments in the emulsifying agent(s), which is the mean of a normalGaussian distribution curve and is from about 4 to about 250, preferablyfrom about 40 to 150, more preferably 40 or 100; and are substantiallyoil insoluble as defined above.

The esters formed by the reaction of the fatty acids with polyhydricalcohols are a particularly interesting group of nonionic emulsifiers,in that, depending on the nature of the alcohol used, they may bepredominantly hydrophilic and are especially suitable as oil-in-wateremulsifiers.

An example of an ester-linkage surfactant which is a good emulsifyingagent is: ##STR7##

Nonionic emulsifying agent(s) with amide linkages are compounds of thegeneral formula: ##STR8## where R is any hydrocarbon group, preferablyan alkyl radical containing from about 8 to about 21 carbon atoms, morepreferably R is C₉ H₁₉ ; and each of y₁ and y₂ is an integer thatrepresents the average number of ethylene oxide units or segments in theemulsifying agent(s), which is the mean of a normal Gaussiandistribution curve and is from about 4 to about 250, preferably fromabout 40 to 150, more preferably 40 or 100; and are substantially oilinsoluble as defined above.

Another nonionic emulsifying agent(s) that has been found to be suitablein the process of this invention is polyethoxylated alcohol(s) havingthe general formula:

    R--O--(CH.sub.2 --CH.sub.2 --O).sub.y --H

wherein R is an alkyl having from about 7 to about 20 carbon atoms and yis an integer that represents the average number of ethylene oxide unitsor segments in the emulsifying agent(s), which is the mean of a normalGaussian distribution curve and is from about 4 to about 250. Morepreferably, R is an alkyl having from about 12 to about 18 carbon atomsand y is from about 120 to about 180.

In a more preferred embodiment of the present invention, the emulsifyingagent(s) is or are those emulsifying agent(s) selected from theethoxylated alkylphenol compounds having a molecular weight distributionwith a dispersity of from about 1.0 to about 5.0, a weight averagemolecular weight of from about 1966 to about 9188, and the generalformula: ##STR9## wherein n₁ is an integer and has a value of from about7 to about 20, preferably 11, and y₁ is an integer having a value offrom about 4 to about 1000; and wherein at least about 50% by weight ofthe emulsifying agent(s) comprises the ethoxylated alkylphenol compoundhaving a molecular weight of from about 1966 to about 9188. Theemulsifying agent(s) has at least one ethoxylated alkylphenol compoundhaving the general formula: ##STR10## wherein n₁ has a value of fromabout 7 to about 20, preferably 11; and y₁ is greater than 100,preferably greater than 100 but less than 1000, and the ethoxylatedalkylphenol compound of general formula (5A) preferably comprises atleast 1% by weight (more preferably from 1% to 90% by weight) of theemulsifying agent(s).

More preferably, the dispersity of the molecular weight distribution ofthe emulsifying agent(s) represented by general formula (5) is fromabout 1.0 to about 2.5, most preferably about 1.0 to 2.0. The weightaverage molecular weight of the emulsifying agent(s) is more preferablyfrom about 3726 to about 6548, most preferably from about 4606 to 5668.More preferably, at least about 70% by weight (most preferably, at leastabout 85% by weight) of the emulsifying agent(s) comprises theethoxylated alkylphenol compound having a molecular weight of from about1966 to about 9188.

The emulsifying agent(s) in the present invention may also be thoseemulsifying agent(s) selected from the ethoxylated dialkylphenolcompounds having a molecular weight distribution with a dispersity offrom about 1.0 to about 5.0, a weight average molecular weight of fromabout 2519 to about 11,627, and the general formula: ##STR11## whereinn₁ is an integer and has a value of from about 7 to about 18, n₂ is aninteger and has a value of from about 7 to about 18, and y₂ is aninteger having a value of from about 4 to about 1000; and wherein atleast about 50% by weight of the emulsifying agent(s) comprises theethoxylated dialkylphenol compound having a molecular weight of fromabout 2519 to about 11,627. The emulsifying agent(s) has at least oneethoxylated dialkylphenol compound having the general formula: ##STR12##wherein n₁ has a value of from about 7 to about 18, n₂ has a value offrom about 7 to about 18, and y₂ is greater than 100, preferably greaterthan 100 but less than 1000; and the ethoxylated dialkylphenol compoundof general formula (6A) preferably comprises at least 1% by weight (morepreferably from 1% to 90% by weight) of the emulsifying agent(s).

More preferably, the dispersity of the molecular weight distribution ofthe emulsifying agent(s) represented by the general formula (6) is fromabout 1.0 to about 2.5, most preferably about 1.0 to 2.0. The weightaverage molecular weight of the emulsifying agent(s) is more preferablyfrom about 4714 to about 8547, most preferably from about 6039 to about7227. More preferably, at least about 70% by weight (most preferably, atleast about 85% by weight) of the emulsifying agent(s) comprises theethoxylated dialkylphenol compound having a molecular weight of fromabout 2519 to about 11,627.

The emulsifying agent(s) may be a combination of the ethoxylatedalkylphenol compounds having the general formula (5) and the ethoxylateddialkylphenol compounds having the general formula (6) in any percent byweight proportion provided that the dispersity of the molecular weightdistribution of the entire combination is from about 1.0 to about 5.0(more preferably about 1.0 to about 2.5 and most preferably about 1.0 to2.0), and the weight average molecular weight in the combination of theemulsifying agent(s) [or in general formula (5) and/or in generalformula (6)] is about 1966 to about 11,627 (more preferably about 3726to about 8547, most preferably about 4606 to about 7227). Furthermore,the entire combination should comprise at least 50% by weight (morepreferably at least about 70% by weight, most preferably at least about85% by weight) of the ethoxylated alkylphenol compound and theethoxylated dialkylphenol compound wherein the ethoxylated alkylphenolcompound has a molecular weight of from about 1966 to about 9188 and theethoxylated dialkylphenol compound has a molecular weight of from about2519 to about 11,627. More preferably, the compounds having the generalformula (5) are from about 30% by weight to about 80% by weight of thecombination. Furthermore, at least 1% by weight (preferably 1% to 90% byweight) of the combination of the ethoxylated alkylphenol compoundhaving the general formula (5) and the ethoxylated dialkylphenolcompound having the general formula (6) comprises the ethoxylatedalkylphenol compound having the general formula (5A) and/or theethoxylated dialkylphenol compound having the general formula (6A),where y₁ and y₂ are both greater than 100, preferably greater than 100but less than 1000.

Dispersity of the molecular weight distribution of the polymericemulsifying agent(s) is defined as the ratio of the weight-averagemolecular weight (M_(w)) of the emulsifying agent(s) to thenumber-average molecular weight (M_(n)) of the emulsifying agent(s), orM_(w) /M_(n). M_(n) is biased toward the lower molecular weightfractions in the polymeric emulsifying agent(s) while M_(w) is biasedtoward the higher molecular weight fractions. Dispersity depends on thebreadth of the molecular weight distribution for the polymericemulsifying agent(s) and measures the polydispersity in the polymericemulsifying agent(s).

The weight-average molecular weight M_(w) is obtained from conductinglight scattering measurements on the emulsifying agent(s) and is definedas ##EQU1## where w_(x) is the weight-fraction of molecules whose weightis M_(x). M_(w) can also be defined as ##EQU2## where C_(x) is theWeight concentration of M_(x) molecules, C is the total weightconcentration of all the polymeric emulsifying agent(s) molecules, N_(x)is the number of moles whose weight is M_(x), and the followingrelationships hold: ##EQU3##

The number-average molecular weight M_(n) is determined by themeasurement of colligative properties such as freezing point depression(cryoscopy), boiling point elevation (ebulliometry), osmotic pressure,and vapor pressure lowering. M_(n) is defined as the total weight w ofall the molecules in the polymeric emulsifying agent(s) divided by thetotal number of moles present. Stated alternatively, the number-averagemolecular weight is defined by: ##EQU4## where the summations are from 1to the number of different sizes of polymer molecules in the emulsifyingagent(s), and N_(x) is the number of moles whose weight is M_(x).

For a comprehensive discussion of dispersity, M_(w), and M_(n), andother macromolecular science properties, such as the physical andorganic chemistry of the reactions by which polymer molecules aresynthesized, see the following publications: Principles ofPolymerization by Odian (copyright and published in 1970 by McGraw-HillInc.); Introduction to Polymer Science and Technology: An SPE Textbookby Kaufman et al. (copyright and published in 1977 by John Wiley & SonsInc.); Principles of Polymer Chemistry by Flory (copyright and publishedin 1953 by Cornell University); and Macromolecules by Elias (Volume 1and 2; copyright in 1977 by Plenum Press, New York, and published in1977 by John Wiley & Sons, Ltd.). All of these publications areincorporated entirely herein by reference hereto.

As will be more thoroughly discussed hereinafter in the Examples for themore preferred emulsifying agent(s) represented by the general formulas(5) and/or (6), the shear life (the measure of the stability of anemulsion) of formed oil-in-water emulsions utilizing the more preferredemulsifying agent(s) are commercially acceptable (i.e. equal an emulsionshear stability to or greater than 40 mins.) provided that the followingparameters are conformed to or are followed:

(1) the dispersity of the molecular weight distribution for theemulsifying agent(s) is from about 1.0 to about 5.0 (more preferably1.0-2.5, most preferably 1.0-2.0);

(2) the weight average molecular weight of the emulsifying agent(s) hasa value of from about 1966 to about 11,627 (more preferably from about3726 to about 8547, most preferably from about 4606 to about 7227),depending on which of the emulsifying agent(s) are employed, thoserepresented by the general formula (5) and/or those represented by thegeneral formula (6); and

(3) that at least 50% by weight (more preferably at least about 70% byweight, most preferably at least about 85% by weight) of the emulsifyingagent comprises the ethoxylated alkylphenol compound having a molecularweight of from about 1966 to about 9188 and/or the ethoxylateddialkylphenol compound having a molecular weight of from about 2519 toabout 11,627.

In another more preferred embodiment of the present invention,especially when the oil-in-water emulsion(s) are to be subterraneouslyformed in a short period of time (e.g 0.10 to 20 secs.), the emulsifyingagent(s) is or are those emulsifying agent(s) selected from theethoxylated alkylphenol compounds having a molecular weight distributionwith a dispersity of from about 1.0 to about 5.0, a weight averagemolecular weight of from about 558 to about 2504, and the generalformula: ##STR13## wherein n₁ is an integer and has value of from about7 to about 14, preferably 8, and y₁ is an integer having a value of fromabout 4 to about 200; and wherein at least about 50% by weight of theemulsifying agent(s) comprises the ethoxylated alkylphenol compoundhaving a molecular weight of from about 558 to about 2504. Theemulsifying agent(s) has at least one ethoxylated alkylphenol compoundhaving the general formula: ##STR14## wherein n₁ has a value of fromabout 7 to about 14, preferably 8; and y₁ is greater than 100,preferably greater than 100 but less than 200, and the ethoxylatedalkylphenol compound of general formula (7A) preferably comprises atleast about 1% by weight (more preferably from about 1% to about 10% byweight) of the emulsifying agent(s).

More preferably, the dispersity of the molecular weight distribution ofthe emulsifying agent(s) represented by general formula (7) is fromabout 1.0 to about 3.0, most preferably about 1.0 to 2.0. The weightaverage molecular weight of the emulsifying agent(s) is more preferablyfrom about 646 to about 1844, most preferably from about 866 to 1404.More preferably, at least about 70% by weight (most preferably, at leastabout 85% by weight) of the emulsifying agent(s) comprises theethoxylated alkylphenol compound having a molecular weight of from about558 to about 2504.

The emulsifying agent(s) may be a combination of the ethoxylatedalkylphenol compounds having the general formula (7) and emulsifyingagent(s) selected from the ethoxylated alkyl compounds having amolecular weight distribution with a dispersity of from about 1.0 toabout 5.0, a weight average molecular weight of from about 2458 to about4218, and the general formula: ##STR15## wherein n₁ is an integer andhas a value of from about 9 to about 14, preferably 11, and y₁ is aninteger having a value of from about 4 to about 300; and wherein atleast about 50% by weight of the emulsifying agent(s) comprises theethoxylated alkylphenol compound having a molecular weight of from about2458 to about 4218. The emulsifying agent(s) represented by generalformula (8) has at least one ethoxylated alkylphenol compound having thegeneral formula: ##STR16## wherein n₁ has a value of from about 9 toabout 14, preferably 11; and y₁ is greater than 100, preferably greaterthan 100 but less than 300, and the ethoxylated alkylphenol compound ofgeneral formula (8A) preferably comprises at least about 1% by weight(more preferably from about 1% to about 75% by weight) of theemulsifying agent(s).

More preferably, the dispersity of the molecular weight distribution ofthe emulsifying agent(s) represented by general formula (8) is fromabout 1.0 to about 3.0, most preferably about 1.0 to 2.0. The weightaverage molecular weight of this emulsifying agent(s) is more preferablyfrom about 2898 to about 3778, most preferably from about 3118 to 3558.More preferably, at least about 70% by weight (most preferably, at leastabout 85% by weight) of the emulsifying agent(s) comprises theethoxylated alkylphenol compound represented by general formula (8)having a molecular weight of from about 2458 to about 4218.

The ethoxylated alkylphenol compounds having the general formula (7) andthe ethoxylated alkylphenol compounds having the general formula (8) arepreferably combined or mixed in a percent by weight proportion such thatthe ethoxylated alkylphenol compounds having the general formula (7)preferably comprise from about 60% by weight to about 85% by weight ofthe combination or mixture, and the ethoxylated alkylphenol compoundshaving the general formula (8) preferably comprise from about 15% byweight to about 40% by weight of the combination or mixture. Morepreferably, the combination or mixture of the ethoxylated alkylphenolcompounds having the general formula (7) and the ethoxylated alkylphenolcompounds having the general formula (8) comprises from about 70% byweight to about 80% by weight of the ethoxylated alkylphenol compoundshaving the general formula (7) and from about 20% by weight to about 30%by weight of the ethoxylated alkylphenol compounds having the generalformula (8).

The emulsifying agent(s) selected from the ethoxylated alkylphenolcompounds having the general formula (7) are particularly valuable insubterraneously forming (i.e., "down hole") oil-in-water emulsions in acommercially acceptable period of time and having a commerciallyacceptable shear life. A commercially acceptable period of time may bedefined as that period of time ranging from about 0.10 secs. to about 20secs. A commercially acceptable shear life has been defined as anemulsion shear stability equal to or greater than 40 mins. For down holepurposes it is desired that oil-in-water emulsion(s) be formed quicklyand with a commercially acceptable shear life so that the high viscosityhydrocarbon being produced can be readily transported to the surface ofthe earth without the high viscosity hydrocarbon plugging the welltubing and/or retarding the transportation of the produced highviscosity hydrocarbon, and/or otherwise curtailing the production of thehigh viscosity failure of the oil-in-water emulsion because of acommercially unacceptable shear life, it may be necessary to pull thewell tubing to unplug or replace well tubing.

Subterranean oil-in-water emulsions are formed with the emulsifyingagent(s) selected from the ethoxylated alkylphenol compounds having thegeneral formula (7) by agitating (e.g. dynamically and/or statically)the produced hydrocarbon with an emulsifying composition at atemperature of from about 35° F. to about 170° F. and wherein theemulsifying composition comprises an aqueous phase and a minor amount ofthe emulsifying agent(s) selected from the ethoxylated alkylphenolcompounds having the general formula (7). The agitating comprises mixingbelow the surface of the earth and in proximity to the producinghydrocarbon formation the produced hydrocarbon with the emulsifyingcomposition for a period of time ranging from about 0.10 sec. to about20 secs., and preferably in a shear field with an intensity ranging fromabout 50 sec.⁻¹ to about 10,000 sec.⁻¹ (preferably 50 sec.⁻¹ to 5,000sec.⁻¹). The emulsifying agent(s) selected from the ethoxylatedalkylphenol compounds represented by the general formula (7) causeexcellent oil-in-water emulsion(s) to be formed with a commerciallyacceptable shear life and within 0.10 to 20 secs. when mixed with anaqueous phase and a produced hydrocarbon at a temperature of from about35° F. to about 170° F.

As will be more thoroughly discussed hereinafter in the Examples for theother more preferred emulsifying agent(s) represented by the generalformula (7), the time to form quality oil-in-water emulsions utilizingthe other more preferred emulsifying agent(s) represented by the generalformula (7) is commercially acceptable (i.e., if formed within 0.10 to20 secs.) provided that the following parameters are conformed to or arefollowed:

(1) the dispersity of the molecular weight distribution for theemulsifying agent(s) is from about 1.0 to about 5.0 (more preferably1.0-3.0, most preferably 1.0-2.0);

(2) the weight average molecular weight of the emulsifying agent(s) hasa value of from about 558 to about 2504 (more preferably from about 646to about 1844, most preferably from about 866 to about 1404);

(3) that at least 50% by weight (more preferably at least about 70% byweight, most preferably at least about 85% by weight) of the emulsifyingagent comprises the ethoxylated alkylphenol compound having a molecularweight of from about 558 to about 2504; and

(4) the temperature of the emulsifying composition (and hydrocarbon) isfrom about 35° F. to about 170° F.

It has been discovered that if the temperature of the emulsifyingcomposition, or hydrocarbon plus emulsifying composition, includingthose emulsifying agent(s) selected from the ethoxylated alkylphenolcompounds represented by general formula (7), is above about 170° F.,oil-in-water emulsion(s) do not form, unless the emulsifying agent(s)selected from the ethoxylated alkylphenol compounds represented bygeneral formula (7) are admixed with or otherwise combined withemulsifying agent(s) selected from those ethoxylated alkylphenolcompounds having general formula (8). As was previously mentioned, thecombination or admixture of the ethoxylated alkylphenol compounds havingthe general formula (7) and the ethoxylated alkylphenol compounds havingthe general formula (8) comprises from about 60% by weight to about 85%by weight (more preferably 70% to 80% by weight) of the ethoxylatedalkylphenol compounds having the general formula (7), and from about 15%by weight to about 40% by weight (more preferably 20% to 30% by weight)of the ethoxylated alkylphenol compounds having the general formula (8).By the admixing or the otherwise combining of the ethoxylatedalkylphenol compounds having general formula (7) with the ethoxylatedalkylphenol compounds having general formula (8), the temperature of theemulsifying composition (or the emulsifying composition plushydrocarbon) may be as high as the boiling point temperature of theemulsifying composition (or the emulsifying composition plushydrocarbon) which typically is about 212° F., depending on thesubterranean pressure, the exact constituency (and the mixing proportionof the various constituencies) of the emulsifying composition and thehydrocarbon, etc.

As will be more thoroughly discussed hereinafter in the Examples for theother more preferred emulsifying agents comprising the mixture orcombination of the emulsifying agent(s) represented by the generalformula (7) and the general formula (8), the time to form qualityoil-in-water emulsions utilizing the mixture or combination of theemulsifying agent(s) represented by the general formula (7) and/or withthe emulsifying agent(s) represented by the general formula (8) iscommercially acceptable (i.e., if formed within 0.10 to 20 secs.)provided that the following parameters are conformed to or are followed:

(1) the dispersity of the molecular weight distribution for theemulsifying agent(s) represented by general formula (7) is from about1.0 to about 5.0 (more preferably 1.0-3.0, most preferably 1.0-2.0);

(2) the weight average molecular weight of the emulsifying agent(s)represented by general formula (7) has a value of from about 558 toabout 2504 (more preferably from about 646 to about 1844, mostpreferably from about 866 to about 1404);

(3) that at least 50% by weight (more preferably at least about 70% byweight, most preferably at least about 85% by weight) of the emulsifyingagent comprises the ethoxylated alkylphenol compound represented bygeneral formula (7) having a molecular weight of from about 558 to about2504; and (4) the dispersity of the molecular weight distribution forthe emulsifying agent(s) represented by general formula (8) is fromabout 1.0 to about 5.0 (more preferably 1.0-3.0, most preferably1.0-2.0);

(5) the weight average molecular weight of the emulsifying agent(s)represented by general formula (8) has a value of from about 2458 toabout 4218 (more preferably from about 2898 to about 3778, mostpreferably from about 3118 to about 3558); about 70% by weight, mostpreferably at least about 85% by weight) of the emulsifying agentcomprises the ethoxylated alkylphenol compound represented by generalformula (8) having a molecular weight of from about 2458 to about 4218;

(7) n₁ in general formula (8) is from about 9 to about 14, as if n₁ isbelow 9 or above 14, it has been discovered that oil-in-water emulsionsof commercial acceptability do not generally form; and

(8) from about 60% by weight to about 85% by weight of the mixture orcombination is the emulsifying agent(s) represented by general formula(7), and if less than 60% by weight or greater than 85% by weight of theemulsifying agent(s) represented by general formula (7) is employed, ithas been discovered that oil-in-water emulsions of commercialacceptability do not generally form.

The emulsifying agent(s) used in the practice of the invention mustenable formation of the oil-in-water emulsion(s) at elevatedtemperatures and retention of stability at ambient temperatures. Unlessbroad-based for such functionality, a mixture of two or more emulsifiersis employed, and is particularly preferred.

In yet another more preferred embodiment of the present invention, theemulsifying composition(s) comprising the aqueous medium, theethoxylated alkylphenol compounds having the general formula (7) and theethoxylated alkylphenol compounds having the general formula (8), in anysuitable percent by weight proportion such as any of the previouslymentioned percent by weight proportions, are injected directly through awell/wellbore into a subterranean hydrocarbon-bearing reservoir orformations having a hydrocarbon. When the emulsifying composition(s) forthis embodiment of the present invention contacts the hydrocarbon at atemperature below about the phase inversion temperature (P.I.T.) for theoil-in-aqueous phase emulsion to be produced, an oil-inaqueous phaseemulsion is formed within the subterranean hydrocarbon-bearingreservoir. Typically, the emulsifying composition(s) contacts and mixeswith at least a portion of the hydrocarbon (and connate water) in situbelow about the P.I.T. to form or produce the oil-in-aqueous phaseemulsion within the subterranean hydrocarbon-bearing reservoir, leavinga residual quantity of the hydrocarbon therein that did not formulate anoil-in-aqueous phase emulsion with the emulsifying composition(s). Aswas previously mentioned, the P.I.T. for the formed oil-inaqueous phaseemulsion is generally between about 180° F. to about 210° F., dependingon the exact consistency of the oil-in-aqueous phase emulsion and theparticular percent by weight proportions in which the constituents arecombined. Preferably, after a known quantity of the emulsifyingcomposition(s) is injected through the well/wellbore and into thehydrocarbon-bearing formation or reservoir, steam and/or hot water(i.e., water with a temperature of 150° F. to 250° F., depending on thepressure) is subsequently injected into the same hydrocarbon-bearingreservoir to follow the emulsifying composition(s). The steam and/or hotwater accomplishes the dual objectives of thermally stimulating theformation by heating the same to raise the temperature and lower theviscosity of in situ hydrocarbon which facilitates oil-in-aqueous phaseemulsion formation, while simultaneously pushing or driving theemulsifying composition(s) away from the wellbore and into the formationfor contact, mixing and interacting with in situ hydrocarbons that arenot in close proximity to the wellbore. Subsequently, the steam and/orhot water injection is terminated after the emulsifying composition hasbeen sufficiently dispersed into and throughout the reservoir, followedby a shut-in of the well/wellbore, allowing the reservoir to soak for asufficient period of time (e.g. one to ten days) to maximize and/oroptimize the formulation of oil-in-aqueous phase emulsion. After thesoak period, the well/wellbore is reopened, and oil-in-aqueous phaseemulsion can be recovered by any suitable means for producing orrecovering, such as with any of the pumps described in Chapter 11entitled "Facilities, Operational Problems, and Surveillance" in thebook Thermal Recovery by Michael Prats copyrighted 1982 by AmericanInstitute of Mining Metallurgical and Petroleum Engineers, published bySociety of Petroleum Engineers (Henry L. Doherty, Memorial Fund ofAIME). The entire process may be repeated to remove residual hydrocarbonand/or oil-in-aqueous phase emulsion remaining within the reservoir orformation and not having been recovered.

The emulsifying composition(s) containing the ethoxylated alkylphenolcompounds having the general formulas (7) and (8) are thermally stableup to a temperature of about 600° F. or slightly higher, and aregenerally not adsorbed by the sands and clays of reservoir formations.The emulsifying composition(s) forms a low-viscosity aqueous phasecontinuous emulsion with improved mobility in the subterraneanreservoir, and causes the reduction of residual oil saturation withincreased ultimate recovery of the original reservoir hydrocarbons.Furthermore, concomitant with recovering the viscosity of in situhydrocarbons, there is increased or accelerated hydrocarbon productionwith a corresponding reduction in thermal losses. Production period canbe extended for those wells having a bottom hole temperature less thanthe usual 90° to 100° C. range, resulting in a reduction in the steam(and/or hot water)/oil ratio. Furthermore still, by employing theemulsifying composition(s) containing the ethoxylated alkylphenolcompounds having the general formulas (7) and (8) for producinghydrocarbons from subterranean formations, the emulsifyingcomposition(s) can be used for mobility control in steamflood orwaterflood operations, and for improved sweep efficiency as a result ofemulsion formation or injections into the high permeability zones toprevent channeling.

In a preferred embodiment of the present invention, a coemulsifyingcomposition is injected directly through the well/wellbore into thehydrocarbon-bearing reservoir prior to or before the injection of theemulsifying composition(s) comprising the ethoxylated alkylphenolcompounds having the general formula (7) and the general formula (8).The coemulsifying composition may be any suitable coemulsifyingcomposition (e.g. anionic and/or nonionic) that can initially beadsorbed on the reservoir rock or formation such as to insure noadsorption of the emulsifying composition(s) comprising the ethoxylatedalkylphenol compounds having the general formulas (7) and (8) as thesame is being injected. While, as was previously indicated, theemulsifying composition(s) does not generally adsorb on sands and clays,in order to insure such nonadsorption, the coemulsifying composition(s)is employed for ultimate preventative purposes. Preferably, thecoemulsifying composition(s) comprises an aqueous phase and acoemulsifying agent(s) selected from alkylarylsulfonates,lignosulfonates, and mixtures thereof. Lignosulfonates (or ligninsulfonates) are metallic sulfonate salts made from lignin of sulfitepulpmill liquors and have molecular weights ranging from about 1000 toabout 20,000. More particularly, lignosulfonates are by-products of thesulfite process for separating cellulose pulp from wood and are formedby the reaction of SO₂ and Ca(HSO₃)₂ with wood which is typically amixture composed of 67 to 80% holocellulose and 17 to 30% lignin,together with low percentages of resins, sugars, a variable amount ofwater, and potassium compounds. Lignosulfonates do not possess awell-characterized chemical structure, but are polyanionic naturalpolymers. The alkylarylsulfonates preferably possess the general formulaRC₆ H₄ SO₃ M wherein R is an alkyl having from 7 to 15 carbon atoms andM is an alkali metal (i.e., lithium, sodium, potassium, rubidium, cesiumor francium), hydrogen, or ammonium or triethanolammonium orisopropylammonium. The coemulsifying composition(s) preferably comprisesfrom about 0.05 vol. % to about 4.0 vol. % or higher of thecoemulsifying agent. The quantity of coemulsifying composition(s)employed may be any suitable amount, depending on the type orcharacteristics of the reservoir formation. Preferably, the quantity ofcoemulsifying composition(s) employed is from about 10% by wt. to about100% by wt. of the emulsifying composition(s), more preferably 20% to50% by wt. Stated alternatively, the proportion or ratio by wt. of thecoemulsifying composition(s) to the emulsifying composition(s) is from0.10 to 1.0, more preferably from 0.20 to 1.0 to about 0.50 to 1.0. Theobject is not so much to formulate an oil-in-aqueous phase with thecoemulsifying composition(s), but to provide a coemulsifyingcomposition(s) having an appropriate quantity of coemulsifying agentsuch that when the coemulsifying composition(s) is injected into thehydrocarbon-bearing reservoir ahead of the emulsifying composition(s),it is adsorbed on or to or by the reservoir rock or formation in orderto further or ultimately reduce or prevent or further curtail anypossibility of adsorption of the subsequent following emulsifyingcomposition(s) onto the reservoir rock or formation. It should beunderstood that obviously, some oil-in-aqueous phase emulsion will beformulated with the coemulsifying composition(s), but the primarypurpose of the coemulsifying composition(s) is to coat and adsorb ontothe reservoir rock or formation to cut down or reduce the quantity ofemulsifying composition(s) to be employed, thus making the process moreeconomical since the emulsifying composition(s) is typically moreexpensive than the coemulsifying composition(s). The employment of thecoemulsifying composition(s) in combination with the emulsifyingcomposition(s) is not only more economical, but there is also animprovement in the recovery of the hydrocarbon, especially when theemulsifying composition(s) is followed by steam and the well/wellbore isshut-in for a soak period. By way of example only, if a combined 5000gal. quantity of both coemulsifying composition(s) and emulsifyingcomposition(s) is employed in a ratio of from about 0.1 to 1.0 in theprocess of this invention for recovering oil from a subterraneanhydrocarbon-bearing reservoir, there is a 2 to 40% improved recoverythan if 5000 gal. of the emulsifying composition(s) or the coemulsifyingcomposition(s) is employed alone or in a ratio other than 0.1 to 1.0.

The method of this invention employing the ethoxylated alkylphenolcompounds having the general formulas (7) and (8), or the same incombination with the initial injection of the coemulsifyingcomposition(s), may be practiced in any suitable reservoir and theinvention is not to be unduly restricted to a particular type ofreservoir or formation. For example, the reservoir may be a sandformation or a rock formation. It may be fractured or unfractured. Thehydrocarbon or oil in the reservoir may be any weight or gravity, but asindicated the alkylphenol compounds having general formulas (7) and (8)are particularly suitable for heavy oils or hydrocarbon. The method forthis embodiment of the invention has been proven particularly useful inan unconsolidated shallow sand formation and is potentially useful inany subterranean reservoir with little or no natural drive, particularlyreservoirs with relatively high permeability and relatively highoil/water ratios in the produced fluids. It is to be appreciated thatthe success of the method will vary with the specific geology of aparticular reservoir; for instance, factors such as reservoir porosityor permeability will influence the extent of penetration of theemulsifying composition(s) into the reservoir and the effectiveness ofoil-in-aqueous phase displacement and recovery.

The method of this invention employing the ethoxylated alkylphenolcompounds having the general formulas (7) and (8), or the same incombination with the initial injection of the coemulsifyingcomposition(s), may be employed in either primary, secondary, ortertiary recovery. Primary recovery is dependent on the driving forcesprovided by the gases and connate waters existing in contact with theoil in the reservoir. Before the natural driving forces required forprimary recovery are depleted, problems are sometimes encountered whichprevent the removal of hydrocarbon from the formation itself or from thewells drilled into it. For example, materials such as paraffins, waxes,and asphalts can accumulate in the formation and the wellbore,restricting or blocking the flow of oil. The ethoxylated alkylphenolcompounds having the general formulas (7) and (8), or the same incombination with the initial injection of the coemulsifyingcomposition(s), have been developed and employed in the method of thisinvention such as to remove the flow-restricting materials. Following aprimary recovery, the compounds having general formulas (7) and (8), orthe same in combination with the initial injection of the coemulsifyingcomposition(s), may be used in the method of this invention as asecondary energy source required for continued production of oil fromhydrocarbon-bearing formations. A conventional secondary recovery methodusually entails injecting fluids into wells to drive oil out of thereservoir, and typical secondary oil recovery methods are waterfloodingand immiscible gas flooding. The method of this invention would employthe ethoxylated alkylphenol compounds having the general formulas (7)and (8), or the same in combination with the initial injection of thecoemulsifying composition(s), to flood the zones to form oil-in-aqueousphase emulsions with any hydrocarbons remaining after primary recovery.Tertiary oil recovery, also known as enhanced oil recovery (EOR), isrecovery of oil which cannot be recovered by either primary or secondarymethods. The aim of tertiary oil recovery methods is to reduce oilsaturation. One method of achieving this aim is by reducing theviscosity of the oil remaining in the reservoir. Viscosity reduction isachieved through the application of heat or by the injection of fluidssuch as the emulsifying composition(s) containing the ethoxylatedalkylphenol compounds having the general formulas (7) and (8), or thesame in combination with the initial injection of the coemulsifyingcomposition(s). Tertiary oil recovery methods employing heat have beenperformed in single wells and are referred to as thermal "huff and puff"methods. A fireflood "huff and puff" method is a thermal "huff and puff"method. Other thermal "huff and puff" methods have involved theinjection of steam into a formation where it is allowed to soak for atime sufficient to lower the viscosity of the oil remaining in thereservoir. The reduction in viscosity permits the oil to be pumped backout of the same well through which steam was injected. One embodiment ofthe method of this invention as previously explained above is avariation on the steam "huff and puff" enhanced oil recovery method.

In one preferred embodiment of this invention for formulatingoil-in-aqueous phase emulsion with the compounds having general formulas(7) and (8), or the same in combination with the initial injection ofthe coemulsifying composition(s), and with a viscous, heavy crude oil ina petroleum reservoir, at least one well is extended from the earth'ssurface down into the bottom of a subterranean petroleum reservoir thatcontains the viscous heavy crude oil. After the well has been extended,the in situ oil-in-aqueous phase emulsion operation is commenced for apredetermined period of time in proximity to the bottom of thesubterranean petroleum reservoir by injecting emulsifying composition(s)containing the alkylphenol compounds having the general formulas (7) and(8) into the injection well in order to establish an emulsion formingzone. Alternatively, as has been previously indicated, prior to orbefore the injection of the emulsifying composition(s), thecoemulsifying composition(s) is injected directly through thewell/wellbore and into the hydrocarbon-bearing reservoir. After anemulsion forming zone has been established in accordance with thedesired pressures and temperatures, the emulsion forming zone is movedand distributed outwardly away from the injection well by the hot waterand/or steam. After the emulsion forming zone has been positioned at adesired distal location, the injection of the hot water and/or steam isterminated, and the injection well is shut-in for a predetermined periodto permit the hydrocarbon/viscous heavy crude oil in the petroleumreservoir to undergo a soak period in order to formulate theoil-in-aqueous phase emulsion and to decrease the viscosity of viscousheavy crude oil imposed over or underlying the steam treated zone. Asthe viscosity of the viscous heavy crude oil decreases, it begins toflow downwardly into the emulsion forming zone in order to formadditional oil-in-aqueous phase emulsion. The formulated oil-in-aqueousphase emulsion may be produced from one or more production wells thatare drilled down into the bottom of the petroleum reservoir where theformulated oil-in-aqueous phase emulsion accumulates and resides. Thenumber of production wells that may be drilled may vary in accordancewith any configuration desired, such as an inverted five-spot ornine-spot or a line drive mode of operation. In an inverted five-spotmode of operation, the injector well is the center well of thefive-spot, and production wells comprise the other four spots of theconfiguration which resembles the configuration on dominoes or dice froman overhead view. In other words, the injection well is in the center ofa square, from an overhead view, with four production wells lying in thecorners of the square. The inverted nine-spot mode of operation issimilar to the inverted five-spot, that is, the injection well lies inthe center of a square, from an overhead view, with four productionwells lying in the corner of the square and four more production wellseach lying in a line between two corner wells. In a line-drive mode ofoperation, a plurality of injection wells are employed to inject steamand/or emulsifying compositions into a formation causing advance of theemulsion forming zone in a more or less straight line parallel to a lineintersecting the plurality of injection wells. This mode of operationmay be enhanced through the use of horizontal bore holes in theformation for both injection and production.

The length of the soak period for this invention will vary depending onthe characteristics of the heavy crude oil within the petroleumreservoir, particularly viscosity of the reservoir oil. We havediscovered that the soak period should be from at least about one day toabout one year, more preferably one to ten days. During the soak period,the oil-in-aqueous phase emulsion continues to be formulated and theviscosity of the heavy crude oil imposed over or overlying the emulsionforming zone decreases and the oil starts to flow downwardly (i.e., bygravity) in order for the flowing oil to be emulsified. Thermallycracked products resulting from high temperature steam are available tobe emulsified into the oil-in-aqueous phase emulsion.

After the soak period has been terminated, after a predetermined amountof time which would be the time necessary to allow the majority of theheavy crude oil to be emulsified into the oil-in-aqueous phase emulsionand to flow downwardly in order to be converted and/or emulsified, thewells are re-opened in order to produce oil-in-aqueous phase emulsionand upgraded crude oil from the bottom of the petroleum reservoir. Itshould be understood that the oil-in-aqueous phase emulsion and theupgraded crude oil in the bottom of the reservoir may be produced fromany production well by any conventional means utilized in that secondaryor tertiary recovery means.

It has been discovered that if, prior to forming the oil-in-aqueousphase emulsion, the emulsifying composition(s) is heated to above theP.I.T. (e.g. above 200° F., preferably 200° F. to 600° F., morepreferably 250° F. to 400° F.) and subsequently followed by cooling tobelow the P.I.T., the oil-in-aqueous phase emulsion formed after coolingto below the P.I.T. has a greater or enhanced stability compared to anoil-in-aqueous phase emulsion formed where the emulsifyingcomposition(s) was not heated to above the P.I.T. Thus, in anotherembodiment of the present invention, the emulsifying composition(s) isinitially heated to a temperature above the P.I.T. for theoil-in-aqueous phase emulsion to be formed, such as a temperature fromabout 200° F to about 600° F; and subsequently injected through awell/wellbore and into a subterranean hydrocarbon-bearing reservoir orformation having a hydrocarbon. The heating of the emulsifyingcomposition(s) can be accomplished by any suitable means and at anysuitable location, such as on the surface of the earth, or whiletraveling down the well/wellbore and employing the use of anytemperature gradient, or while being injected into the reservoir orformation itself. One preferred means for heating the emulsifyingcomposition(s) is to accompany the emulsifying composition(s) withsteam, which typically would have a temperature of from about 212° F. toabout 600° F., preferably from about 215° F. to about 400° F. As theemulsifying composition(s) travels down the well/wellbore, the steamcommingles and mixes intimately with the emulsifying composition(s)causing the temperature of the latter to inherently rise, preferablyabove the P.I.T. Obviously, the amount or degree of temperatureelevation primarily depends on the temperature of the steam. The hotterthe steam the higher is the temperature elevation of the emulsifyingcomposition. The steam also provides a transport medium which assists indispersing and carrying the emulsifying composition(s) into andthroughout the reservoir or formation for contacting and mixing with thein situ hydrocarbon. With the temperature of the emulsifyingcomposition(s) being above the P.I.T., no oil-in-aqueous phase emulsionis formulated when the emulsifying composition(s) contact and mix within situ hydrocarbon. After the desired quantity of above P.I.T.emulsifying composition(s) has been injected into the reservoir orformation, steam or steam and hot water continually follows theemulsifying composition(s)/steam mixture to distribute the above P.I.T.emulsifying composition(s) at desired distances throughout the reservoiror formation for contacting the in situ hydrocarbon. As the dispersedemulsifying composition(s) cools below the P.I.T. while in contact within situ hydrocarbon, oil-in-aqueous phase emulsion formulates with agreater or enhanced stability than had not the emulsifyingcomposition(s) been heated above the P.I.T. The cooling of theemulsifying composition(s) to below the P.I.T. typically takes placeafter the well/wellbore has been shut-in and during the soak period.After all of the emulsifying composition(s) has cooled to below theP.I.T. and enhanced stability oil-in-aqueous phase emulsion hasformulated, the well/wellbore is reopened to recover the enhancedstability oil-in-aqueous phase emulsion.

Another preferred means for heating the emulsifying composition is toheat the aqueous phase of the emulsifying composition to above theP.I.T. prior to mixing with the emulsifying agent such that theemulsifying composition(s) to be injected into the reservoir has atemperature above the P.I.T. This above P.I.T. emulsifying compositionis distributed through the reservoir or formation with steam and/or hotwater. When the emulsifying composition(s) cools below the P.I.T. whilein contact with hydrocarbons, oil-in-aqueous phase emulsion(s)formulates in situ with greater or enhanced stability.

A further preferred means for heating the emulsifying composition is toaccompany the emulsifying composition(s) with hot water (instead ofsteam) which, as previously indicated, could have a temperature of 150°F. to 250° F. (depending on the pressure) or even higher provided thehot water does not vaporize into steam. Preferably the hot water wouldbe of such temperature as to raise the overall temperature of theemulsifying composition above the P.I.T. The quantity of hot water (orsteam) should be targeted such that the eventually formed oil-in-aqueousphase emulsion has a selected aqueous phase and connate water content offrom about 10 percent to about 70 percent by weight aqueous phase andconnate water and a viscosity sufficiently low such as to be recoveredfrom the reservoir or formation. As the mixture of hot water andemulsifying composition(s) is injected into the reservoir, it contactsthe hydrocarbon (and connate water) at a temperature above the P.I.T.;thus, no oil-in-aqueous phase formulates until the emulsifyingcomposition(s) begins to cool during the soak period to a temperaturebelow the P.I.T. As was previously indicated above, the mixture ofemulsifying composition(s) and hot water is followed before the soakperiod by steam and/or hot water to distribute the above P.I.T.emulsifying composition(s) at preferred locations and distancesthroughout the reservoir for coming in contact with distal hydrocarbons.After shutting in the well/wellbore and soaking for a desired suitableperiod, such as one to ten days or longer, the well/wellbore is reopenedto recover enhanced, stable oil-in-aqueous phase emulsion.

As was previously indicated, the emulsifying composition(s) containingthe ethoxylated alkylphenol compounds having the general formulas (7)and (8) can be employed for mobility control in steamflood/waterfloodoperations and to improve sweep efficiencies. The efficiency of awaterflood operation is severely affected by the channeling of theinjected water through a high permeability zone or a high watersaturation zone (e.g. a bottom water). Furthermore, the economics ofmany steamflood enhanced oil recovery projects are strongly affected bysteam override (gravity segregation) and steam channeling. Cores takenfrom heavy oil reservoirs at the termination of a steam drive clearlyshow this upward migration of the steam and consequent segregation ofthe displacing and displaced fluids. Oil-in-aqueous phase emulsionsformulated with the emulsifying composition(s) containing theethoxylated alkylphenol compounds having the general formulas (7) and(8), or the same in combination with initially injecting oil-in-aqueousphase emulsions formulated with the coemulsifying composition(s) inaccordance with the previously mentioned procedure above, can be used toincrease the efficiency of a waterflood operation by plugging the highwater mobility zone and following this plugging procedure withwaterflooding. As the oil-in-aqueous phase emulsion is being injectedinto the reservoir formation, a greater quantity of the emulsion entersthe more permeable zones since it will take the path of leastresistance. As this occurs, the flow of subsequent following waterbecomes more restrictive within the reservoir formation and water beginsto flow into less permeable zones which contain residual hydrocarbons,resulting in greater sweep efficiency. The oil droplets contained in theoil-in-aqueous phase emulsion can create blockage in high permeabilityzones by the lodging of the oil droplets within pore throats of thereservoir formation. The oil droplets not only block pores of throats,especially those smaller than the size of the oil droplets, but they arealso captured in pore walls and in crevices to create an ensemble of oildroplets crowding together in a single pore throat.

Oil-in-aqueous phase emulsions formulated with the emulsifyingcomposition(s) containing the ethoxylated alkylphenol compounds havingthe general formulas (7) and (8), or the same in combination withinitially injecting oil-in-aqueous phase emulsions formulated with thecoemulsifying composition(s), can increase the economic performance ofmany steamflood operations by plugging the steam-swept override zones orchanneling zones with the emulsions in order to direct subsequentfollowing steam to zones of higher oil saturation and, thus, improve theratio of oil produced to steam injected. The channeling or steam-sweptoverride zones are zones of high permeability and if not blocked off orplugged will consume a large portion of injected steam to ultimatelyaffect the economic performance of the steamflooding operation. Afterthe oil-in-aqueous phase emulsions have plugged these more permeablezones, the mobility of the steam into high permeability zones is reducedand injected steam flows into the less permeable zones containingresidual hydrocarbons, commencing a thermal sweep-out of such residualhydrocarbons.

The formulation of oil-in-aqueous phase emulsions with the emulsifyingcomposition(s) containing the ethoxylated alkylphenol compounds havingthe general formulas (7) and (8), or the coemulsifying composition(s)containing the coemulsifying agent(s), may be formulated by any of theprocedures indicated herein and at any desired suitable location. By wayof example only, the oil-in-aqueous phase emulsion can be formed on thesurface of the earth, between the surface of the earth and the bottom ofthe well, or in proximity to the bottom of the well contiguous to aperforated zone, all for subsequent injection into the reservoirformation. The oil-in-aqueous phase emulsion can be formed spontaneouslyin situ for subsequent passage or movement into the desired zones by adrawing/mobilizing agent, such as water and/or steam and/or gas. Whereand/or how the oil-in-aqueous phase emulsions are formulated is notcritical since the emulsifying composition(s) containing the ethoxylatedalkylphenol compounds having the general formulas (7) and (8) arecompatible with fresh water or brine (i.e., up to 10%, or 100,000 ppm,NaCl and/or CaCl₂), are chemically stable at reservoir conditions, arethermally stable at elevated temperatures, and are essentially immunefrom extremes in pH, oxygen content, metal content and other impuritiespresent in the reservoir formation and which do not adversely affect thestability of the emulsifying composition(s). It should be understoodthat after the waterflooding or the steamflooding operations have beenterminated, the oil-in-aqueous phase emulsion may be recovered byconventional techniques, such as by natural drives from thelow-viscosity emulsion flowing out of the high permeability zones andinto well/wellbore.

Any of the emulsifying composition(s) of this invention may be used indownhole emulsification which allows increased production from a heavycrude or bitumen well. Downhole emulsification refers to the formationof a water continuous emulsion in the production tubing of a wellproducing heavy crude or bitumen. The benefit gained by formation of theemulsion is a great reduction in the viscosity of the crude in the welltubing, allowing a significant increase in the production rate. Thefactor limiting production in many conventional heavy crude wells is thetime required for the sucker rod and pump plunger to fall to their downposition after an upstroke. The viscous drag on the rod results in veryslow production. The low viscosity of a water continuous emulsioneliminates this constraint. A water continuous emulsion may be formed inthe well casing by mixing the crude and brine flowing into the pump withemulsifying composition(s). This operation causes the water to becomethe continuous phase with the crude being encapsulated as droplets or aslarger discrete masses. The free water phase lubricates the contact ofthe crude with the production tubing and the sucker rod to accomplishthe desired reduction in drag. Shear forces are required to form thecrude into the separate particles surrounded by water. The flow of thecrude, water and surfactant through the passages within the downholepump provides sufficient shear for this purpose. The relative quantitiesof crude, water and surfactant flowing into the pump are crucial forproper well operation. If too little water is present at the pump inletthen the resulting viscosity of the water continuous emulsion will notbe as low as desired. If the water fraction is too high, then a very lowviscosity emulsion will be formed which does not have the capacity tocarry formation sand (which is often associated with heavy crudeproduction operations) out of the well. During periods when the well maynot be operating, the accumulated sand may settle in the tubing andresult in failure to restart the well. The best operation of a downholeemulsification system is obtained with water concentrations in the 15%to 50% range.

The quantity of emulsifying agent employed in the emulsifyingcomposition(s) injected can affect the properties of the produced watercontinuous emulsion. If too little emulsifying agent is used, anemulsion will not be formed. If excessive emulsifying agent is injected,very small and stable oil droplets may be formed which are difficult toseparate from the emulsion. The desired concentration of emulsifyingagent in the total produced fluids is 200 to 1000 parts emulsifyingagent per million parts of crude with a preferred concentration of 300to 500 ppm. Optimal operation of the system is achieved by adjusting theemulsifying agent level so that the low viscosity of water continuousemulsion is achieved without the formation of small oil droplets.

The emulsifying composition(s) added to form oil-in-aqueous phaseemulsion may be injected into the system by any suitable means. In thepreferred injection system for the embodiment of the invention in FIGS.16 and 17, a downhole pump and sucker rod (not shown in the drawings) isreplaced with a special diluent injection pump, generally illustrated as400, and a hollow sucker rod assembly 402. The injection pump 400 issecured to the end of the hollow sucker rod assembly 402 as bestillustrated in FIG. 17, and both are removably disposed through a tubing404 which is generally concentrically situated in a casing 406perforated at 408 for the passage of formation fluids. The injectionpump 400 comprises a hollow upper plunger 410 secured to a lower end ofthe hollow rod 402, and a hollow cross over fitting means 412. A hollowlower plunger 414 having a traveling valve 416 integrally connects tothe hollow cross over fitting means 412. The tubing 404 has a by-passconduit 418 connecting from a lower part of the tubing 404 (as bestillustrated in FIG. 17) down between the lower portion of the tubing 404and the casing 406, terminating below or in close proximity to astanding valve 420. On the surface of the earth (see FIG. 16), a hollowflexible hose 422 connects to the hollow rod 402. Water from water tank424 is introduced into the hose 422 to form emulsifying composition(s)which is pumped down the hollow sucker rod assembly 402, throughpassageways indicated by arrows A in FIG. 17 and into the by-passconduit 418. As the emulsifying composition(s) leaves conduit 418, itmixes with crude passing through perforations 408 from the reservoirformation to form oil-in-aqueous phase emulsion which is subsequentlypumped (or sucked) through standing valve 420 and through valve 416 intothe lower plunger 414 via arrows B and through valve 416 via arrow C,into the hollow cross-over 412 via arrow D, into the hollow upperplunger 410 via arrow E and passageways indicated as dotted lines p inFIG. 17, and out of the hollow upper plunger 410 via arrow F into theannulus between the tubing 404 and the hollow sucker rod 402. On thesurface of the earth, the oil-in-aqueous phase emulsion leaves theannulus between the tubing 404 and the hollow sucker rod 402 throughconduit 430 to be discharged into a heated production tank 432 wheremost of the water/brine is separated from the emulsion. This water/brineis passed through conduit 434 into the water tank 424 for recycling intothe injection system as it contains a significant portion of theemulsifying agent(s) and reduces the quantity of make-up emulsifyingagent(s) required.

In the preferred injection system for the embodiment of the invention inFIG. 18, a concentrated emulsifying composition(s) 431 is meteredcontinuously directly into the annulus between the well casing 406 andthe tubing 404. In contrast to the embodiment in FIGS. 16 and 17, nochanges were made to a conventional downhole pump, illustrated generallyas 450 in FIG. 18, a solid conventional sucker rod 452, or any of theother conventional components The emulsifying composition(s) 431 dripsor flows intermittently or otherwise into the annulus between the casing406 and the tubing 404, mixes with the formation fluids at the bottom ofthe hole in the casing annulus, and eventually reaches an inlet of thedownhole pump 450 where a water continuous emulsion is formed to bepumped up the hollow tubing 404 for discharge through conduit 430. Inthe injection system for the embodiment of the invention in FIG. 19,which is a variation of the method described for FIG. 18, the additionof emulsifying composition(s) 431 into the casing annulus is on a batchbasis rather than continuously. A head H of emulsifying composition(s)is created. The emulsifying composition(s) 431 is blended with formationfluids in the annulus and is gradually mixed with the crude coming intothe well to form a water continuous emulsion. The concentration of theemulsifying composition(s) gradually decreases to a point at which itbecomes ineffective. The quantity and frequency of batch emulsifyingcomposition(s) injections is adjusted to maintain a minimum acceptablelevel of emulsifying composition(s) at the downhole pump inlet. Thismethod may also include the addition of water or brine with theemulsifying composition(s) to increase the water concentration of theproduction fluid to a minimal level of approximately 20% which isrequired for formation of the desired low viscosity emulsion. Theaddition of a large batch of water and emulsifying composition(s) intothe well casing has a further benefit, in comparison to the injectionembodiments in FIGS. 16 and 17 and 18. The benefit is the result ofraising the fluid level in the well casing, a point of which causes thefluid in the casing annulus to flow through perforations 408 and intothe reservoir adjacent to the well. This fluid, containing emulsifyingcomposition(s) solution, cleans the reservoir in this area and improvesinflow into the well. As a result, the pressure drop related to crudeand water flow into the well is reduced and a higher fluid level issustained in the casing. Another preferred injection system is theembodiment depicted in FIG. 20 and is similar to FIG. 18, but employsthe use of a separate tube 460 parallel to production tubing 04.Emulsifying composition(s) is conducted or pumped through flexible hose422 (or solid conduit), and into and through the tube 460 whichterminates in close proximity to perforations 408. The emulsifyingcomposition(s) commingles with oil leaving the reservoir formationthrough perforations 408 to form an emulsion that is pumped to thesurface of the earth through production tubing 404 via pump 450.

As has been previously stated, the emulsifying agent(s) of thisinvention has to be mixed with a water or the pipeline-transportableoil-in-water emulsion(s) of this invention cannot be formulated. Theemulsifying agent(s) should not contact the produced hydrocarbon crudedirectly before being admixed with water. Stated alternatively, theemulsifying composition(s) of this invention which is to be admixed orcombined with the produced hydrocarbon crude have to contain water, orthe oil-in-water emulsion(s) of this invention will not be produced tobe pipeline-transportable.

As has also been previously stated, the freezing point of theemulsifying composition(s) and/or the oil-in-water emulsions may belowered by the addition of a compound which lowers the freezing point ofwater, which for the purpose of this invention is preferably ethyleneglycol. The oil-in-water emulsion(s) of this invention are watercontinuous and through the addition of ethylene glycol into theemulsifying composition(s), the freezing point of the continuous phase(i.e. water) of the oil-in-water emulsion(s) is lowered. Preferably,ethylene glycol is added to the emulsifying composition(s) such that theemulsifying composition(s) and/or the water continuous phase of theoil-in-water emulsion(s) comprise from about 0.5% by wt. to about 80% bywt. ethylene glycol, more preferably from about 0.5% by wt. to about 30%by wt.

In order to form a more stable oil-in-water emulsion (or watercontinuous emulsion) when the produced hydrocarbon crude is Athabascabitumen, the water or aqueous phase preferably has a pH of above 4.0,preferably from about 6.0 to about 13.0, such as 7 to 9 and 6 to 8. Thisis especially true when brine is employed as the aqueous phase. If brineis being utilized, salinity becomes another factor. It has been foundthat with brine as the aqueous additive for the produced hydrocarboncrude, the salinity of the brine should be at least about 1.5% by wt.salt (i.e. NaCl). It should be pointed out that no upper limit on saltconcentration has been determined and may be that quantity of salt whichsupersaturates the brine, or that upper amount of salt which goes intosolution.

More stable oil-in-water emulsion(s) are formed, especially when theproduced hydrocarbon crude is Athabasca bituemen, with the use of thebiopolymer xanthan which is an additional stability enhancer. Biopolymerxanthan is added to the emulsifying composition(s) such that theemulsifying composition(s) and/or the water continuous phase of theoil-in-water emulsion(s) such that the oil-in-water emulsion(s)comprises biopolymer xanthan in a ratio of from about 25 ppm to about5,000 ppm by weight of the produced hydrocarbon crude. Statealternatively, biopolymer xanthan is provided in a concentration of fromabout 25 to about 5,000 ppm by weight of the produced hydrocarbon crude.

Xanthan has outstanding resistance to shear degradation, and isinsensitive to waters with high salt content. Xanthan containsD-glucose, D-mannose, and D-glucurontic acid. It is believed to have acellulose-like backbone composed of repeating β-D-(1-4) glucose unitswith mannose and glucuronic acid present in side chains, and mannosepartially modified with acetyl and pyruvate ketol groups.

Xanthan molecular weight is reported to be greater than one million. Thebiopolymer exists in solution as a helix in native form. The presentlyaccepted structure for xanthan is as follows: ##STR17##

Biopolymer xanthan may be purchased commercially as FLOCON® Biopolymer4800 from Pfizer Inc.

In another embodiment of the present invention, the viscosity of theeffluent oil-in-water emulsion(s) through and/or from conduit 110, or inthe emulsion tank 122, may be controlled and/or reduced to facilitatethe transportation of the oil-in-water emulsion(s) of this invention.This result is achieved by tailoring the droplet size distribution inthe produced oil-in-water emulsion. Lower viscosity for the oil-in-wateremulsion(s) reduces the power required for pipeline pumping operations,and also decreases the stress placed on the oil-in-water emulsion(s)which could cause oil droplets in the oil-in-water emulsion(s) tocoalesce and increase in size. Formation of water continuous emulsionswith a tailored oil droplet size, results in a lower emulsion viscosityfor the effluent oil-in-water emulsion(s).

The viscosity of a suspension of oil particles or oil droplets is afunction of the viscosity of the water continuous phase, theconcentration of the oil particles, and the distribution of oil particlesize. An approximation of the viscosity of an oil-in-water emulsion isgiven by the following equation: ##EQU5## where μ=oil-in-water emulsionviscosity (cs)

μ=viscosity of the water continuous phase (cs)

φ=volume fraction of the dispersed oil phase

φ_(p) =maximum packing fraction for the emulsion oil droplet sizedistribution

The equation illustrates that the viscosity of an oil-in-water emulsionmay be reduced if the oil droplet size distribution results in a largermaximum packing fraction. This reduction may be accomplished by formingthe oil-in-water emulsion such that a wide range of oil droplet sizesresults, or by the formation of a bimodal oil droplet size distribution.By way of example only, in comparison to a monodisperse oil-in-wateremulsion with φ=0.5, a bimodal oil-in-water emulsion with an oil dropletsize ratio of 5 to 1 theoretically has a viscosity reduced by a factorof about 10, assuming spherical and non-interacting oil particles.

The viscosity of the effluent oil-in-water emulsion(s) of the presentinvention may be controlled and/or reduced by varying the flow rate (andthe shear rate) of the mixture of emulsifying composition(s) and theproduced hydrocarbon crude through the static shearing and mixing device108; or alternatively, by splitting (as illustrated FIG. 2) the flow ofthe mixture of emulsifying composition(s) and produced hydrocarbon crudein conduit 50 into conduit 130 and conduit 132, and flowing therespective split mixture through the conduit 130 and conduit 132 atdistinguishable or different shear rates [shear rate =(8×velocity ininches/sec.) divided by static mixer diameter in inches]. In order tocontrol these two flow rates and to ensure that the respective shearrates are distinguishable or different, flow rate control valve 134 andflow rate control valve 136 are provided within conduit 130 and 132,respectively. Valves 134 and 136 may be set and controlled such that theshear rates of the respective mixtures of the emulsifying composition(s)and produced hydrocarbon crude through static shearing and mixing means108A and 108B are indeed different. The shearing and mixing means 108Aand 108B may have the same or different diameter. The respectiveeffluent oil-in-water emulsion(s) from static shearing and mixing means108A and 108B are conducted or transported through conduits 138 and 140,respectively, and into the conduit 110 of FIG. 1 wherethrough the twoadmixed or combined mixtures are sent to the emulsion tank 122 (see FIG.1). As illustrated in FIG. 1, before settling into the emulsion tank122, the temperature of the two admixed emulsion mixtures should bereduced below about 120° F. with heat exchanger 120 in order to increasethe stability of the formulated bimodal or multimodal oil-in-wateremulsion(s) that has a lower viscosity than either the viscosity of theeffluent oil-in-water emulsion(s) in conduit 138 or the viscosity of theeffluent oil-in-water emulsion(s) conduit 140. The viscosity of theformulated bimodal oil-in-water emulsion(s) comprising the two effluentoil-in-water emulsion(s) from conduits 138 and 140 is not the average ormean of the viscosity of the two effluent oil-in-water emulsion(s) inconduits 138 and 140, but is lower than either. It is to be understoodthat while only a pair of parallel static shearing and mixing devices108A and 108B have been illustrated and represented, three (3) or moreparallel devices may be employed within the spirit and scope of thisinvention.

A bimodal or multimodal oil-in-water emulsion(s) may also be formed inthe emulsion tank 122 by varying the flow rate (and the shear rate) ofthe mixture of emulsifying composition(s) and produced hydrocarbon crudethrough the static shearing and mixing device 108, and collecting theeffluent oil-in-water emulsion(s) produced from the static shearing andmixing device 108 at various flow (and shear) rates in the emulsion tank122. The collected effluent oil-in-water emulsion(s) produced fromvarious flow rates through device 108 mix and combine in the emulsiontank 122 to form bimodal or multimodal oil-in-water emulsion(s) having alower viscosity than the viscosity of oil-in-water emulsion(s) producedfrom the static shearing and mixing device 108 with one flow (and shear)rate. Thus, by way of example only, the viscosity of a bimodaloil-in-water emulsion(s) produced by flowing a mixture of emulsifyingcomposition(s) and produced hydrocarbon crude through device 108 at 50in./sec. for 10 minutes, and combining the resulting oil-in-wateremulsion(s) with the oil-in-water emulsion(s) formulated fromsubsequently flowing the same mixture through the device 108 at 30in./sec. for 10 minutes, would be lower than the respective viscositiesof the oil-in-water emulsion(s) produced at 50 in./sec. or 30 in./sec.

The size of the oil droplets in the oil-in-water emulsion(s), or in thebimodal oil-in-water emulsion(s), of the present invention tend toincrease in size during flow through a pipe, such as pipeline 123. Thiseffect could change the benefits of this invention by changing the oildroplet size distribution through augmentation of the size of oildroplets. To maintain within the pipeline 123, or the like, a bimodal ormultimodal nature of the oil-in-water emulsion(s), or to even initiallyunimodal produce a bimodal or multimodal oil-in-water emulsion(s) from aoil-in-water emulsion, a stream of the multimodal oil-in-wateremulsion(s) or the unimodal oil-in-water emulsion(s) may be withdrawnperiodically from the pipeline 123, such as through a conduit 142 asillustrated in FIG. 3, and subjected to static shearing and mixingthrough the use of a flow rate control valve 144 and the static shearingand mixing device 108. As depicted in FIG. 3, flow rate control valve144 would control the flow rate of any multimodal or unimodalemulsion(s) through the device 108 to reduce the size of the oil dropletwithin the particular type of emulsion(s) such that when the effluentoil-in-water emulsion(s) exiting the device 108 through a conduit 146that is in communication with the pipeline 123 is recombined with thestream of flowing oil-in-water emulsion(s) that has by-passed conduit142, the bimodal or multimodal nature of the oil-in-water emulsion(s) isre-established. Valve 148 is a variable flow rate valve that restrictsthe flow of oil-in-water emulsion(s) therethrough such that some of theoil-in-water emulsion(s) flowing through pipeline 123 is forced to flowthrough conduit 142. Valve 150 would control the flow of oil-in-wateremulsion(s) and effluent oil-in-water emulsion(s) (from device 108)through the conduit 146. This withdrawal process may be conducted asmany times as necessary along the pipeline 123 to maintain watercontinuous emulsion(s) which have a lower viscosity than if thewithdrawal process was not employed. Instead of using static shearingand mixing device 108 in the withdrawal process in order to maintainlower viscosity in the flowing oil-in-water emulsion(s), a centrifugalpump (of the type used in commercial pipelines) may be utilized toreshear the flowing oil-in-water emulsion(s). Any of the mixing and/orreshearing step(s) may be accompanied by the addition of moreemulsifying composition(s) if needed.

In another embodiment of the present invention, a bimodal or multimodaloil-in-aqueous phase emulsion(s) may be formed with any of theemulsifying agent(s) of the present invention by varying the residencetimes and/or the shear rate of the mixture of emulsifying composition(s)and produced hydrocarbon crude in any suitable dynamic shearer and mixer(e.g. a rotor stator mixer, etc.), and collecting the effluentoil-in-aqueous phase emulsion(s) emanating from the dynamic shearer andmixer at various residence times and/or shear rates in any suitable tankor container, such as emulsion tank 122. The collected effluentoil-in-aqueous phase emulsion(s) produced from various residence timesand/or shear rates in any suitable dynamic shearer and mixer combine inthe emulsion tank 122 to form bimodal or multimodal oil-in-aqueous phaseemulsion(s) having a lower viscosity of oil-in-aqueous phase emulsion(s)produced from one dynamic shearer and mixer having a fixed shear rateand/or residence time of the emulsifying composition(s) and the producedhydrocarbon crude in the dynamic shearer and mixer; or from the staticshearing and mixing device 108 with one flow (and shear) rate. Thus, byway of example only, the viscosity of a bimodal oil-in-aqueous phaseemulsion(s) produced by positioning for 4 secs. a mixture of emulsifyingcomposition(s) and produced hydrocarbon crude in a dynamic shearer andmixer having a shear field intensity of 500 sec.⁻¹, and combining theresulting oil-in-aqueous phase emulsion(s) with the oil-in-aqueous phaseemulsion(s) formulated from subsequently positioning for 4 secs. thesame mixture in the same dynamic shearer and mixer having a shear fieldintensity of 6,000 sec.⁻¹, would be lower than the respectiveviscosities of the oil-in-aqueous phase emulsion(s) produced with anintensity of 500 sec.⁻¹ or 6,000 sec.⁻¹. Similar results can be obtainedby varying the residence time while holding the shear field intensitygenerally constant or fixed. In this embodiment of the presentinvention, a bimodal or multimodal oil-in-aqueous phase emulsion(s) maybe formed with two or more dynamic shearers and mixers in parallel, orwith one (or more) dynamic shearers and mixers in parallel with one (ormore) static shearing and mixing device, such as device 108. Thecollected effluent oil-in-aqueous phase emulsions produced from the two(or more) dynamic shearers and mixers having different shear rates (orshear field intensities) and/or with different residence times for themixture of emulsifying composition(s) and hydrocarbon crude in therespective dynamic shearers and mixers combine to form bimodal ormultimodal oil-in-aqueous phase emulsion(s) having a lower viscositythan the viscosity of oil-in-aqueous phase emulsion(s) produced from anyone of the two (or more) dynamic shearers and mixers. Similarly, thecollected effluent oil-in-aqueous phase emulsions produced from one (ormore) dynamic shearers and mixers in parallel with one (or more) staticshearing and mixing devices combine to form bimodal or multimodaloil-in-aqueous phase emulsion(s) having a lower viscosity than theviscosity of oil-in-aqueous phase emulsion(s) produced from any singleone dynamic shearer and mixer or from any single one static shearing andmixing device. Typically, each dynamic shearer and mixer has a differentshear rate (or shear field intensity) and/or the residence times of theemulsifying composition-crude mixture in each dynamic shearer and mixerare distinct from each other. Typically further, each static shearingand mixing device has or produces a different shear rate from the otherstatic shearing and mixing devices. Thus, by way of example only, abimodal or multimodal oil-in-aqueous phase emulsion may be produced bypositioning for a generally known period (e.g. 0.10 sec to 5 mins. orhigher) a portion of an emulsifying composition-hydrocarbon crudemixture in a first dynamic shearer and mixer having a predetermined orknown shear rate (e.g. a shear field intensity from 50 sec.⁻¹ to about10,000 sec.⁻¹ or higher) to produce a first oil-in-aqueous phaseemulsion having a first viscosity, leaving a remaining portion of theemulsifying composition-hydrocarbon crude mixture that has not beenpositioned in the first dynamic shearer and mixer. The remainingemulsifying composition-hydrocarbon crude mixture is positioned for agenerally known period of time in a second dynamic shearer and mixer (orpassed through a static shearing and static mixing device at apredetermined velocity for a predetermined period of time). The seconddynamic shearer and mixer has a shear rate that is different from theshear rate of the first dynamic shearer and mixer, and produces a secondoil-in-aqueous phase emulsion having a second viscosity. When the firstoil-in-aqueous phase emulsion is mixed or commingled with the secondoil-in-aqueous phase emulsion, an oil-in-aqueous phase emulsion isproduced having a viscosity lower than the first viscosity of the firstoil-in-aqueous phase emulsion and lower than the second viscosity of thesecond oil-in-aqueous phase emulsion. The one or more dynamic shearersand mixers and/or one or more static shearing and mixing devices may bein any relationship to each other, such as in parallel or in series.

The static shearing and mixing device 108 (and 108A and 108B) of thisinvention may be any static, in-line mixer that is capable of producingthe oil-in-water emulsion(s) of the invention. Not any static, in-linemixer may be capable of this production. We have discovered thatsuitable static shearing and mixing devices 108, 108A, and 108B for thisinvention are those that employ a stationary baffle means installedwithin a pipe, conduit, or the like, such that the energy of the flowingmixture of emulsifying composition(s) and produced hydrocarbon crudeproduces the required shearing and mixing to produce the oil-in-wateremulsion(s). The stationary baffle means may not be just any bafflemeans which may give unpredictable mixing efficiency as equipment sizeand flow conditions change. Also, just any baffle means may provideappreciable shearing tho mixing only under turbulent flow conditions,whereas the oil-in-water emulsion(s) of this invention are to beproduced under both laminar and turbulent flow conditions.

The static shearing and mixing devices 108, 108A and 108B of thisinvention are to employ a baffle means that provides precise geometricpaths for fluid flow in order to obtain consistent, predictable mixingperformance, regardless of the flow rate of the mixture of emulsifyingcomposition(s) and produced hydrocarbon crude, or equipment dimensions.Preferred static shearing and mixing devices 108, 108A and 108B havebeen determined to be certain of the motionless mixers manufactured byKomax Systems Inc., Long Beach, Calif. and Koch Engineering Company,Inc., Wichita, Kans. The motionless mixers produced by these two producethe oil-in-water emulsion(s) employ a baffle means in a conduit thatshears and mixes simultaneously. Similar designs by other manufacturersmay work equally well.

A preferred static shearing and mixing device 108 (or 108A or 108B)manufactured by Komax Systems, Inc. is illustrated in FIGS. 4, 5, 6, and7, and is more particularly described and illustrated in U.S. Pat. No.3,923,288 which is incorporated herein by reference. Referring in detailnow to FIGS. 4-6, there is seen one embodiment for the static shearingand mixing device 108 (or 108A or 108B) of this invention whichcomprises a conduit 152 having an internal chamber 154 in which aplurality of baffle elements, generally illustrated as 156 and 158, aresized and fitted. Internal chamber 154 is open at the two ends of theconduit 152 such that the mixture of emulsifying composition(s) andproduced hydrocarbon crude may pass over and through the plurality ofbaffle elements 156 and 158 to effect the required shearing and mixingto produce the oil-in-water emulsion(s). A longitudinal axis passesthrough the length of the chamber 154 which has a generally cylindricalconfiguration as is illustrated in FIG. 4. Baffle element 156 is shownin greater detail in FIGS. 5 and 7 and is the mirror image of baffleelement 158 which is shown in greater detail in FIGS. 6 and 7.

Baffle element 156 comprises a flat generally rectangular centralportion 160, the plane of which is to be generally aligned with thelongitudinal axis of the chamber 154. A first set of ears 162 and 164are integrally bound to one side of the central portion 160, and arearcuate and configured at their outer peripheries for a general fitagainst the internal wall of the chamber 154. The first set of ears 162and 164 are bent respectively in an upward and downward directionrelative to the plane of the central portion 160. A second set of ears166 and 168 are integrally bound to the opposite side of the centralportion 160, and like the first set of ears 162 and 164, are bent upwardand downward relative to the plane of the central portion 160. Ears 162and 168 are located diagonally opposite one another across the centralportion 160 and are bent in the same direction relative to the plane ofthe central portion 160. Likewise, ears 164 and 166 are also locateddiagonally opposite one another across the central portion 160 and arealso bent in the same direction relative to the plane of the centralposition 160. The outside peripheral edges of the ears 166 and 168 arealso arcuate and configured for a general fit to the wall of the chamber154.

Baffle element 158, as was previously indicated, is a mirror image ofthe baffle element 156, and in a similar manner comprises a centralportion 170, a first set of ears 172 and 174, and a second set of ears176 and 178. Ears 172 and 178, as well as ears 174 and 176, arediagonally positioned across the central portion 170 with respect to oneanother and are bent in the same direction relative to the plane of thecentral portion 170.

The angle between ears 162-164, 166-168, 172-174, and 176-178 may be anysuitable angle that can provide the shearing and mixing of the mixtureof emulsifying composition(s) and produced hydrocarbon crude to producethe oil-in-water emulsion(s) of this invention. Preferably, the anglebetween the respective set of ears is from about 30° to about 120°.

In a preferred embodiment for the mixing device 108 in FIGS. 4-7, aplurality of baffle elements 156 and 158 are employed in the conduit 152in an alternating fashion, as illustrated in FIG. 4. The baffle elements156 and 158 may be spacedly positioned with respect to each other, orpreferably, as illustrated in FIG. 4, in an abutting relationship withrespect to each other.

When the baffle elements 156 and 158 are in an abutting relationship,ears 172 and 174 of baffle element 158 inter-mesh and/or overlap Withears 166 and 168 of baffle element 156. Similarly, ears 162 and 164 ofelement 156 inter-mesh and/or overlap with ears 176 and 178 of element158; all as illustrated in FIG. 7. The total number of baffle elements156 and 158 used depends on the viscosity of the produced hydrocarboncrude and the degree of mixing desired for the emulsifyingcomposition(s) and the produced hydrocarbon crude. Typically, 6 to 8baffle elements would be employed in the conduit 152.

When at least one each of the baffle elements 156 and 158 are installedin conduit 152 in an abutting relationship, there is a shearing and amixing action taking place on the mixture of emulsifying composition(s)and produced hydrocarbon crude that is being passed in direction of thearrow in FIG. 1 through the conduit 152. A counter-clockwise velocityvector or rotational vector is imposed by ears 166 and 168 of element156 to back-mix the emulsifying composition(s) and the producedhydrocarbon crude and eliminate the streaming or tunneling effects thatcan occur with conventional static mixers. The central flat portion 160transforms the counter-clockwise or rotational vector to a lateral orradial vector. After the mixture of emulsifying composition(s) and theproduced hydrocarbon crude passes the central flat portion 160, ears 162and 164 impose an additional counter-clockwise or rotational velocity tothe mixture which adds somewhat to the lateral or radial vector that isbeing produced by the central flat portion 160. Ears 162 and 164 imposea substantially outward directed radial velocity vector, whereas ears166 and 168 impose a substantially inward directed radial velocityvector, on the mixture of emulsifying composition(s) and producedhydrocarbon crude that is moving longitudinally through the conduit 152.When the mixture leaves baffle element 156 and is passed over baffleelement 158, the ears 176 and 178 and 172 and 174 impose both aclockwise rotating velocity vector, as well as a generally inward andoutward radial vector, respectively.

FIGS. 8-12 shows another embodiment for the baffle means which is to befitted into the conduit 152 having the chamber 154 to define the staticshearing and mixing device 108. The baffle means of FIGS. 8-12 comprisesa plurality of generally identical baffle elements, each generallyillustrated as 180, that are interbound with one another.

Each baffle element 180 comprises a central part 182 which is flat andgenerally rectangular with a plane that is to be generally aligned withthe longitudinal axis of the chamber 154. Each baffle element 180 alsocomprises a flat generally rectangular first part 184 and a flatgenerally rectangular second part 186. The respective planes of thefirst part 184 and the second part 186 are generally normal with thelongitudinal axis of the chamber 154 and the plane of the central part182. When the baffle elements 180 connect with one another, the firstpart 184 of one baffle element 180 attaches integrally to the secondpart 186 of another baffle element 180, as illustrated in FIG. 9.

Each baffle element 180 also comprises a first pair of arms 188 and 190forming a generally V-shape and extending from one half (i.e. the upperhalf relative to when the central part 182 is situated as in FIG. 8) ofthe central part 182 to the first part 184 where it binds therewith. Achanneling member, generally illustrated as 192, extends from the firstpart 184 to another half (i.e. the lower half relative to when thecentral part 182 is situated as in FIG. 8) of the central part 182. Thechanneling member 192 includes a base 194 and a channeling partition 196that secures to and is generally normal to the base 194, and attaches tothe other half of the central part 182. As illustrated in the drawings,there is one opening above the partition 196 and underneath arm 188, andanother opening between the base 194 and underneath the arm 190.

Between the second part 186 and the central part 182 on the other sideof the central part 182 is an inverted mirror image of the pair of arms188-190 and the channeling member 192 including the base 194 and thepartition 196. More specifically, on the other side of the central part182 there is seen a second pair of arms 198 and 200 forming a generallyV-shape and extending from one-half (i.e. the lower half relative towhen the central part 182 is situated as in FIG. 8) of the central part182 to the second part 186 where they bind thereto. A channeling member,generally illustrated as 202, extends from the second part 186 toanother half (i.e. the upper half relative to when the central part 182is situated as in FIG. 8) of the central part 182. Similar to channelingmember 192, channeling member 202 comprises a base 204 and a channelingpartition 206 that is bound to the base 204 in a normal relationship,and attaches to the other half of the central part 182. There is oneopening below the partition 206 and above the arm 200, and anotheropening between the base 204 and above the arm 198.

FIG. 13 represents another embodiment of an end for each of the baffleelements 180. In this embodiment, the channeling member 192 ispositioned on the opposite side of the central part 182. The first pairof arms 188 and 190 form a generally V-shape and extend to the upperhalf of the central part 182 and binds therewith. The channeling member192 extends from the first part 184 down to the lower half of thecentral part 182 and comprises the base 194 and the channeling partition196 that attaches normally to the base 194. Partition 196 also attachesto central part 182 and tapers towards and attaches to the first part184 as well as the arm 188. There is an opening above the partition 196and below the arm 188, and another opening between the base 194 andbelow the arm 190.

By employing the baffle element 180 within the conduit 152, it isbelieved that a number of mixing actions are provided for the mixture ofemulsifying composition(s) and produced hydrocarbon crude. A dividingaction for the mixture is provided between the opening above thepartition 196 and underneath arm 188 and the opening between the base194 and underneath the arm 190 (see FIG. 11). A cross-current mixing isalso provided by the same two openings as illustrated in FIG. 12.Another mixing action is illustrated in FIG. 10 and is back-mixing andcounter-rotating vortices. Eliptical vortices rotating in oppositedirections are produced on both sides of the central part 182 andeliminates the streaming or tunneling effects associated with otherstatic mixing devices. In back-mixing, the mixture of emulsifyingcomposition(s) and produced hydrocarbon crude is orbited in the vortexfrom the front to the back of an element before continuing downstream.

Another embodiment of the static mixing device 108 which can be employedin the process of this invention is manufactured by Koch EngineeringCompany, Inc., Wichita, Kans. and is illustrated in FIGS. 14 and 15.This embodiment of the static mixing device 108 is more particularlydescribed in U.S. Pat. No. 3,785,620 which is incorporated herein byreference thereto. The static mixing device 108 for this embodiment ofthe invention comprises a plurality of baffle elements 208A and 208Bwhich are substantially identical to each other. Baffle elements 208Aand 208B are aligned within the conduit 152 in a contiguous generallyabutting relationship with each baffle element 208B offset atapproximately 90° relative to each baffle element 208A (see in FIG. 14where the baffle elements 208A and 208B are spacedly positioned forclarity).

Referring to FIG. 15, each baffle element 208A and 208B has corrugatedlamellas 210 which are welded to one another to form the particularbaffle element, either 208A and 208B. As shown, different sizes orlengths of individual lamellas 210 are used which increase from the twooutsides toward the middle so that a generally cylindrical shaperesults. The lamellas 210 are in a parallel relationship to thelongitudinal axis of the conduit 152 and are preferably made of a sheetmetal which does not corrode when contacted with the producedhydrocarbon crude and emulsifying composition(s). The corrugations ofeach lamella 210 are of substantially equal slope, with about 45° beingthe preferred slope of each corrugation such that when the corrugatedlamellas 210 are adjoined to one another (such as by welding), aplurality of open, intersecting channels at 45° to the longitudinal axisof the conduit 152 is formed.

The mixture of produced hydrocarbon crude and emulsifying composition(s)enter the conduit 152 and are split into individual streams in theseries of open, intersecting channels for fluid flow. These channelsprovide strong transversal flow and fluid exchange at the wall of theconduit 152. At each channel intersection, a part of the mixture ofproduced hydrocarbon crude and emulsifying composition(s) shears offinto the crossing channel.

As was previously indicated, baffle elements 208A and 208B arepositioned 90° relative to each other, so two-dimensional mixing takesplace over the first baffle element (i.e. either 208A or 208B) andthree-dimensional mixing over all successive baffle elements.Three-dimensional mixing ensures uniformity in the produced oil-in-wateremulsion(s) leaving the conduit 152. Thus, the baffle elements 208A and208B suitably mix the mixture of produced hydrocarbon crude andemulsifying composition(s) in longitudinal and transverse directions bydirecting the part-flows of the mixture in a plurality of criss-crossingzig-zag paths through the length of the baffle elements 208A and 208B.The various mixing actions obtained are such that oil-in-wateremulsion(s) is easily and rapidly obtained over a relative short lengthfor conduit 152.

Through the use of the emulsifying agent(s) in combination with otherfeatures of the invention, oil-in-water emulsion(s) are formulated whichcontain a strong shear stability, enabling them to be suitablecandidates for the pipeline transport of produced hydrocarbon crude,especially for Athabasca bitumen. One physical disadvantage inherent inAthabasca bitumen is its very high viscosity (e.g. about 20,000 cp at100° F.; 300 cp at 200° F.). This physical fact imposes that thetransport of this raw material by conventional pipeline at ambienttemperatures is impossible. The alternative use of a diluent naphtha, orthe like, is unsuitable due to the cost and long-term availability. Theability to transport Athabasca bitumen over long distances byconventional pipeline technology to existing facilities would reduce theproduction costs required for on-site upgrading of this petroleumsource. The oil-in-water emulsion(s) formed in accordance with theinvention are thermally stable and exhibit a strong shear stability.

The static shearing and mixing device 108 may be used to control the oildroplet size in the oil-in-water emulsion(s) of this invention.Generally, the further an oil-in-water emulsion(s) has to be transportedthrough a pipeline, the smaller the oil droplet size in the oil-in-wateremulsion(s) should be since the oil droplets in the oil-in-wateremulsions tend to coalesce and augment as the emulsion(s) travel througha pipeline.

The intensity of the shear field on the mixture of emulsifyingcomposition(s) and produced hydrocarbon crude within the static shearingand mixing device 108 is proportional to the rate of flow of the mixturethrough the device 108. As the shear rate (and the rate of flow) isincreased through the operating range, the size of oil droplets from theproduced hydrocarbon crude become progressively smaller. The shear rateor the rate of flow of the mixture of emulsifying composition(s) andproduced hydrocarbon crude through the mixer should be large enough toimpart sufficient shear on the mixture to produce an oil-in-wateremulsion(s), but not too large as chaotic mixing can cause the oildroplets to recoalesce before being stabilized in the water continuousphase of the oil-in-water emulsion. In a preferred embodiment of theinvention, the flow rate of the mixture of the emulsifyingcomposition(s) and the produced hydrocarbon crude through the device 108is from about 20 in./sec. to about 140 in./sec.

The oil droplet size within an oil-in-water emulsion(s) may be predictedby the following equation:

    d=CD.sup.a-b N.sub.we

where d is the volumetric mean oil droplet size in microns; C is aconstant ranging from about 750 to about 1,500, and represents amultiplier contributing to the absolute disposition in volumetric meandroplet size of the oil; D is the internal diameter in inches for thedevice 108; N_(we) is the dimensionless Weber Number for the fluidflowing through the device 108 and ranges from about 50 to about30(10⁶); a is an exponent which is from about 0.3 to about 1.2,preferably about 0.6; and b is also an exponent ranging in value fromabout 0.2 to about 0.8, preferably about 0.4. The exponents a and b areconstants, which account for the relative variation in the volumetricmeans droplet size of the oil.

N_(we) is the Weber Number, a commonly used dimensionless numberrelating shear forces imparted on the oil droplet to the cohesive forcesholding the oil drop together, defined as ##EQU6## where D is theinternal diameter in inches of device 108; v is the velocity in inchesper second of the fluid flowing through the device 108; p is theoil-in-water emulsion density in lbs. per cubic foot; and σ is theinterfacial tension for the oil-in-water emulsion in dynes per cubiccentimeter. The oil-in-water emulsion density p ranges from about 40lbs./ft³ to about 70 lbs./ft³. The interfacial tension for theoil-in-water emulsion ranges from about 0.25 dynes/cm.³ to about 25dynes/cm³. For a further and more comprehensive discussion of theformula to predict oil droplet size and the defined Weber Number seeIndustrial Engineering Chemistry Process Design & Development, Vol. 13,No. 1, 1974 by Stanley Middleman, which is entirely incorporated hereinby reference thereto. This reference more specifically defines theformula to predict oil droplet size and the formula for the WeberNumber, including each of the variables in the respective formulas andthe manner of determining each.

The invention will be illustrated by the following set-forth exampleswhich are given by way of illustration and not by any limitation. Allparameters such as concentrations, mixing proportions, temperatures,pressure, rates, compounds, etc., submitted in these examples are not tobe construed to unduly limit the scope of the invention.

EXAMPLE I

The oil samples used for these investigations were Westmin crude. Thebrine was Westmin field produced with a pH of about 6.2. The surfaceactive agents used in the testing series were ethoxylated nonyl phenols(NP). They are all members of the general family of nonionic surfaceactive agents of the formula: ##STR18## where y=40 (NP40) and y=100 (NP100). Various concentrations of the respective surface active agents(ranging from 214.3 ppm to about 500 ppm by weight of Westmin Crude)were mixed with the brine to form emulsifying composition(s). Theemulsifying composition(s) was mixed with the Westmin crude at atemperature 160° F.±10° F. An oil-in-water emulsion was formed with theemulsifying-crude mixture by positioning the mixture in a rotor statormixer Mixing energies were 3,000 rpm for 60 secs. The oil-in-wateremulsion(s) produced contained from about 15 percent to about 40 percentby weight brine. The following Table I discloses shear life (which is ameasure of emulsion stability) that was detected for the variousconcentration of emulsifiers:

                  TABLE I                                                         ______________________________________                                        Ratio and Concentration of NP40/NP100                                                                  Shear Life                                           ______________________________________                                        (70:30) 500 ppm NP40 + 214.3 ppm NP100                                                                 17      min                                          (60:40) 428.6 ppm NP40 + 285.7 ppm NP100                                                               13                                                   (50:50) 357.1 ppm NP40 + 357.1 ppm NP100                                                               22                                                   (40:60) 285.7 ppm NP40 + 428.6 ppm NP100                                                               18                                                   (30:70) 214.3 ppm NP40 + 500 ppm NP100                                                                 18                                                   ______________________________________                                    

A 1:1 ratio on NP40 to NP100 produced an oil-in-water emulsion with ahigher shear life than the other ratios.

EXAMPLE II

Repeat Example I but prepare the oil-in-water emulsion(s) only with a 2inch diameter static shearer and mixer embodied by FIGS. 4-7 or FIGS.8-13 or FIGS. 14-15 at a throughput velocity of from about 20 in./sec toabout 140 in./sec. and find that the shear life is greater for eachratio of NP40 to NP100 and also find that the 1:1 ration of NP40 toNP100 produces the highest shear life when compared to the other ratiosof NP40 to NP100. Thus, the oil-in-water emulsion(s) produced through astatic shearer and mixer has a shear life greater than if theoil-in-water emulsion(s) was produced by dynamic mixing.

EXAMPLE III

Example I was repeated for Westmin crude having a pH of about 8.5. TableII below lists the shear life that was found for various concentrationsof emulsifiers:

                  TABLE II                                                        ______________________________________                                        Ratio and Concentration of NP40/NP100                                                                  Shear Life                                           ______________________________________                                        (70:30) 500 ppm NP40 + 214.3 ppm NP100                                                                 12      min                                          (60:40) 428.6 ppm NP40 + 285.7 ppm NP100                                                               16                                                   (50:50) 357.1 ppm NP40 + 357.1 ppm NP100                                                               22                                                   (40:60) 285.7 ppm NP40 + 428.6 ppm NP100                                                               18                                                   (30:70) 214.3 ppm NP40 + 500 ppm NP100                                                                 18                                                   ______________________________________                                    

A 1:1 ratio of NP40 to NP100 produced an emulsion with a higher shearlife than the other ratios.

EXAMPLE IV

Repeat Example III but prepare the oil-in-water emulsion only with a 2inch diameter static shearer and mixer embodied by FIGS. 4-7 or FIGS.8-13 or FIGS. 14-15 at a throughput velocity of from about 20 in./sec.to about 140 in./sec. and find that the shear life is larger for eachratio of NP40 to NP100 and also find that the 1:1 ratio of NP40 to NP100produces the highest shear life when compared to the other ratios ofNP40 to NP100.

EXAMPLE V

Repeat Examples I-IV but immediately cool the respective mixtures of thecrudes plus the emulsifying composition below about 100° F. after theformation of the emulsion and find that the shear life increases foreach oil-in-water emulsion. Thus, the stability of each oil-in-wateremulsion is increased by immediately cooling the formed oil-in-wateremulsion below about 100° F.

EXAMPLE VI

The oil samples used for these investigations were Jibaro crude. Thebrine was synthetic brine with a pH of from about 7.0±1.0 and a NaClcontent of from about 5.0% by wt.±3%. The emulsifiers used in thetesting series were NP40 and NP100. Various concentrations (ranging from0 ppm to about 1428.6 ppm by weight of Jibaro crude) of the respectivesurface active agents were mixed with the brine to form emulsifyingcomposition(s). The emulsifying composition(s) was mixed with the Jibarocrude at a temperature of 160° F.±10° F. An oil-in-water emulsion wasformed with emulsifier crude mixture by positioning the mixture in arotor stator means. Mixing energies were 3,000 rpm for 40 secs. Theoil-in-water emulsion(s) produced contained from about 15 percent toabout 60 percent by weight brine. The following Table III disclose shearlife that was detected for the various concentration of emulsifiers:

                  TABLE III                                                       ______________________________________                                        Ratio and Concentration of NP40/NP100                                                                  Shear Life                                           ______________________________________                                        (100:0) 1428.6 ppm NP40 + 0 ppm NP100                                                                  63      min                                          (50:50) 714.3 ppm NP40 + 714.3 ppm NP100                                                               80                                                   (0:100) 0 ppm NP40 + 1428.6 ppm NP100                                                                  55                                                   (100:0) 1071.4 ppm NP40 + 0 ppm NP100                                                                  35                                                   (50:50) 535.7 ppm NP40 + 535.7 ppm NP100                                                               42                                                   (0:100) 0 ppm NP40 + 1071.4 ppm NP100                                                                  33                                                   ______________________________________                                    

A 1:1 ratio of NP40 to NP100 produced an oil-in-water emulsion with ahigher shear life than the other ratios.

EXAMPLE VII

Repeat Example VI but prepare the oil-in-water emulsion only with a 2inch diameter static shearer and mixer embodied by FIGS. 4-7 or FIGS.8-13 or FIGS. 14-15 at a throughput velocity of from about 20 in./sec.to about 140 in./sec. and find that the shear life is larger for eachratio of NP40 to NP100 and also find that the 1:1 ratio of NP40 to NP100produces the highest shear life when compared to the other ratios ofNP40 to NP100.

EXAMPLE VIII

Repeat Examples VI-VII but immediately cool the respective mixtures ofthe crudes plus the emulsifier composition below about 100° F. after theformation of the emulsion and find that the shear life increases foreach oil-in-water emulsion. Thus, the stability of each oil-in-wateremulsion is increased by immediately cooling the formed oil-in-wateremulsion below about 100° F.

EXAMPLE IX

The oil samples were Athabasca bitumen. The aqueous phase was brinecomprising 3% by wt. NaCl. The emulsifier agent(s) were NP40 and NP100.A 1:1 ratio of NP40 (2857.1 ppm by weight of Athabasca bitumen) andNP100 (2857.1 ppm by weight of Athabasca bitumen) was added to the brineto form emulsifying composition(s). The emulsifying composition(s) wasmixed with the Athabasca bitumen at a temperature of about 165° F.±5° F.The emulsifying-bitumen mixture was placed in a rotor-stator mixer at3000 rpm for 40 secs. No oil-in-water emulsion(s) was produced. Thus,NP40/NP100 could not produce an oil-in-water emulsion with Athabascabitumen.

EXAMPLE X

Repeat Example IX with the emulsifying composition comprising theemulsifying agent as an ethoxylated alkyphenol compound having thegeneral formula: ##STR19## and employed in the brine at a concentrationof about 1428.6 ppm by weight of Athabasca bitumen. The emulsifyingcomposition was mixed with the Athabasca bitumen at a temperature ofabout 190° F.±5° F. The emulsifying-bitumen mixture was placed in arotor-stator at 3000 rpm for 40 secs. An oil-in-water emulsion(s) wasproduced. Thus, while NP40/NP100 could not produce an oil-in-wateremulsion with Athabasca bitumen, the ethoxylated alkylphenol compound ofthis Example X does produce oil-in-water emulsion(s).

EXAMPLE XI

Repeat Example IX with any of the static shearer/mixer and find similarresults.

EXAMPLE XII

Repeat Example X with any of the static shearer/mixer of this inventionand find similar results.

EXAMPLE XIII

The oil samples were Athabasca bitumen. The aqueous phase was brinecomprising 3% by wt. NaCl. A 1:1 ratio of NP40 (1428.6 ppm by weight ofAthabasca bitumen) and NP100 (1428.6 ppm by weight of Athabasca bitumen)was added to the brine to form an emulsifying composition(s). Theemulsifying composition(s) was mixed with the Athabasca bitumen at atemperature of about 160° F. The emulsifying-bitumen mixture was placedin a rotor-stator mixer at 3000 rpm for 40 secs. An oil-in-wateremulsion(s) was produced, but only with a shear life less than one(1)minute. Thus, the NP40/NP100 could not produce with Athabasca bitumen anoil-in-water emulsion with any substantial shear life.

EXAMPLE XIV

Repeat Example XIII with the emulsifying composition comprising theemulsifying agent as an ethoxylated dialkylphenol compound having thegeneral formula: ##STR20## and employed in the brine at a concentrationof about 1428.6 ppm by weight of Athabasca bitumen. The emulsifyingcomposition was mixed with the Athabasca bitumen at a temperature ofabout 190° F.±5° F. The emulsifying-bitumen mixture was placed in arotor-stator at 3000 rpm for 40 secs. An oil-in-water emulsion(s) wasproduced with a substantial shear life. Thus, while NP40/NP100 could notproduce an oil-in-water emulsion with Athabasca bitumen, the ethoxylateddialkylphenol compound of this Example XIV does produce oil-in-wateremulsion(s).

EXAMPLE XV

Repeat Example XIII with any of the static shearer/mixers of thisinvention and find similar results.

EXAMPLE XVI

Repeat Example XIV with any of the static shearer/mixers of theinvention and find similar results.

EXAMPLE XVII

The crude for this Example was PCEJ bitumen. The aqueous phase was brinewith about 1.7% by wt. NaCl. The surfactant was a mixture of 714.3 ppmNP40 (714.3 ppm of NP40 by weight of PCEJ bitumen) and 714.3 ppm NP100(714.3 ppm of NP100 by weight of PCEJ bitumen). The brine andsurfactants were mixed to form an emulsifying composition. Theemulsifying composition and PCEJ bitumen were mixed and passed at atemperature of about 180° F. through a 2.07 in. diameter static mixer ofFIGS. 8-13 at a rate of about 114 in./sec. to form an oil-in-wateremulsion having a water concentration of about 25% by wt. The measuredvolumetric mean oil drop size was 27 microns. The predicted volumetricmean oil drop size from the formula d=CD^(a) N_(we) ^(-b) with C=1000;a=0.5; b=0.35; D=2.07 inches; and N_(we) =109,700, was 25 microns. Thus,the predicted volumetric mean oil drop size was comparable to themeasured volumetric mean oil drop size.

EXAMPLE XVIII

The crude for this Example was Manatokan. The aqueous phase was brinewith about 1.7% by wt. NaCl. The surfactant was a mixture of 714.3 ppmND40 (714.3 ppm of NP40 by weight of Manatokan) and 714.3 ppm NP100(714.3 ppm of NP100 by weight of Manatokan). The brine and surfactantswere mixed to form an emulsifying composition. The emulsifyingcomposition and Manatokan were mixed and passed at a temperature ofabout 160° F. through a 0.20 in. diameter static mixer of FIGS. 4-7 at arate of about 60 in./sec. to form an oil-in-water emulsion having awater concentration of about 28% by wt. The measured volumetric mean oildrop size was 34 microns. The predicted volumetric mean oil drop sizefrom the formula d=CD^(a) N_(we) ^(-b) with C=1000; a=0.5; b=0.35;D=0.20 inches; and N_(we) =1,920, was 32 microns. Thus, the predictedvolumetric mean oil drop size was comparable to the measured volumetricmean oil drop size.

EXAMPLE XIX

The Example is presented to prove that bimodal oil-in-water emulsion(s)has an improved viscosity. The crude was Manatokan. The aqueous phasewas water. The surfactant was a mixture of 714.3 ppm NP40 (714.3 ppm ofNP40 by weight of Manatokan) and 714.3 ppm NP100 (714.3 ppm of NP100 byWeiqht of Manatokan). The emulsifying composition was prepared by mixingwater with the surfactant. Two oil-in-water emulsions were prepared bymixing a known amount of the emulsifying composition(s) with a knownamount of the Manatokan and agitating with a rotor-stator mixer having amixer energy of 3000 rpm for 40 secs. The first oil-in-water emulsion(s)had a mean oil droplet size (μ) of 69.9, a dispersity of 3.27, and aviscosity (cp) of 221. The second emulsion with less Manatokan had amean oil droplet size of 54.9, a dispersity of about 3.56, and aviscosity (cp) of about 198. When 1 liter of the first emulsion wasmixed with 1 liter of the second emulsion a third oil-in-water emulsionwas produced having a mean oil droplet size of about 61.7, a dispersityof about 3.88 and a viscosity (cp) of about 140. Thus, bimodal emulsionhave a lower viscosity than any of its emulsion constituents.

EXAMPLE XX

The crude oil was Athabasca bitumen. The aqueous phase was brinecomprising 3% by wt. NaCl with a pH of 7.0 to 8.0. The surfactant was a50:50 mixture of ##STR21## The oil-in-water emulsion formationtemperature was 164° F. with a rotor/stator at 3000 rpm for 300 sec. Thefollowing Table IV discloses the results of six (6) experimental runswherein biopolymer xanthan was employed in three (3) of the six (6)runs:

                  TABLE IV                                                        ______________________________________                                        Experimental                                                                            Surfactant  Xanthan     Percent                                     Run       Concentration                                                                             Concentration                                                                             Redisperse*                                 ______________________________________                                        1         11,428.6 PPM    714.3 PPM   100%                                    2         11,428.6 PPM    0     PPM   75%                                     3         8,571.4  PPM    714.3 PPM   100%                                    4         8,571.4  PPM    0     PPM   30%                                     5         5,714.3  PPM    714.3 PPM   20%                                     6         5,714.3  PPM    0     PPM    0%                                     ______________________________________                                         *"Percent Redisperse" indicates the amount of emulsion redispersable one      to two hours after initial emulsion formation. This is indicative of the      oil droplets coalescing into a continuous oil phase as the emulsion           stability fails. A value 85% or below is considered to represent an           unstable emulsion (i.e. poor static stability).                          

The above data show that a stable water continuous Syncrude bitumenemulsion formed with a dynamic rotor-stator device cannot be formedwithout the biopolymer xanthan acting as a continuous, water phasethickener and emulsion stabilizer, and cannot be formed below asurfactant concentration of 8,571.4 PPM.

EXAMPLE XXI

The crude oil was Athabasca bitumen. The brine has a pH of about 8.5 andcomprised 3% by wt. NaCl. The surfactant was a 50:50 mixture of DP150and DNP150. The mixer was a static mixer of FIGS. 4-7. The flow rate wasbetween 20 in./sec. and 140 in./sec. The oil-in-water emulsion formationtemperature was 165° F.±5° F. The following Table V discloses theresults of six (6) experimental runs:

                  TABLE V                                                         ______________________________________                                        Experi-                                                                       mental                                                                              Surfactant   Xanthan     % Re-  Shear                                   Run   Concentration                                                                              Concentration                                                                             disperse                                                                             Life*                                   ______________________________________                                        1     8,571.4 PPM  0 PPM       100%                                           2     5,714.3 PPM  0 PPM       100%   138 Min                                 3     4,285.7 PPM  0 PPM       100%   51 Min                                  4     4,285.7 PPM  0 PPM       100%   64 Min                                  5     2,857.1 PPM  0 PPM       100%   24 Min                                  6     2,857.1 PPM  0 PPM       100%   56 Min                                  ______________________________________                                         *"Shear Life" is a test measuring the shear stability of an emulsion. Tha     is, an emulsion after formation is subjected to a shear field via the         laboratory rotorstator at 2000 RPM until the emulsion fails. The time         until failure is defined as the "Shear Life" of an emulsion.             

The above data indicates that redispersable emulsions can be formed witha static mixer without the biopolymer xanthan, and at surfactantconcentration levels below 8,571.4 PPM.

EXAMPLE XXII

The surfactants for this Example were NP 40 and NP 100 in a 1:1 ratio,and DP 150 and DNP 150 in a 1:1 ratio. The aqueous phase was brine. Theoil-in-water emulsions were formed with a 1/2 inch diameter staticshearer and mixer embodied by FIGS. 4-7 or FIGS. 8-13. The surfactantsused were subject to degradation over a long period under stress. If thesurfactants are depleted by degradation, the oil-in-water emulsion mayfail by either phase separation or by inversion into a water-in-oilemulsion. The following table illustrates that with the emulsifiers ofthis invention, such failure is by the phase separation mode and not byinversion:

                                      TABLE VI                                    __________________________________________________________________________                    Total PPM of                                                                  Surfactant           % Nominal                                                to Crude,            Crude to %  Pipe Loop                                                                           Apparent               Run             by Weight                                                                            Static Formation                                                                            Emulsifying                                                                          Duration                                                                           Diameter                                                                            Viscosity, cp          #  Crude Surfactant                                                                           of Crude                                                                             Mixer Type                                                                           Temperature                                                                          Composition                                                                          Hr.  In.   Start                                                                             End                __________________________________________________________________________    PL Manatokan                                                                           NP40/NP100                                                                           1,800  0.5 in. Komax                                                                        160° F.                                                                       65/35   56  0.88  144 28                 64                     (FIGS. 8-13)                                           PL Manatokan                                                                           NP40/NP100                                                                           1,676  0.5 in. Komax                                                                        160° F.                                                                       65/35  113  0.88   90 22                 69                     (FIGS. 8-13)                                           PL PCEJ  NP40/NP100                                                                           2,142  0.5 in. Komax                                                                        175° F.                                                                       70/30  245  0.88  330 40                 68 bitumen             (FIGS. 8-13)                                           PL Athabasca                                                                           DP150  12,307 0.5 in. Komax                                                                        165° F.                                                                       65/35  480   2.059                                                                              200 155                81 bitumen                                                                             DNP150        (FIGS. 4-7)                                            __________________________________________________________________________

With the emulsifier(s) of this invention, failure by separation resultsin a slight decrease in fluid viscosity and permits continued pipelineoperation. The pipe loop runs indicate that phase separation is the modeof transport emulsion failure for various crudes.

EXAMPLE XXIII

The surfactants for this Example were Triblock Pluronic plus tridecylalcohol containing 150 moles ethylene oxide plus a biopolymer (otherthan xanthan). The aqueous phase was brine. Oil-in-water emulsion(s)were attempted to be formed with a 0.5 inch diameter Komax (FIGS. 8-13)or a dynamic mixer. The following Table VII illustrates that theoil-in-water emulsion(s) failed with the emulsifier(s) by inversion:

                                      TABLE VII                                   __________________________________________________________________________                    Total PPM of                                                                  Surfactant    % Nominal                                                       to Crude,     Crude to %  Pipe Loop                           Run             by Weight     Emulsifying                                                                          Duration                                                                           Diameter                            #  Crude Surfactant                                                                           of Crude                                                                             Mixer Type                                                                           Composition                                                                          Hr.  In.   Comments                      __________________________________________________________________________    78 Athabasca                                                                           Triblock                                                                             3,571  Static 70/30  <5 min.                                                                            2 in. Inverted at start                bitumen                                                                             Pluronic +    0.5 in. Mixer            of circulation*                        Tridecyl      (FIGS. 8-13)                                                    Alcohol +                                                                     Biopolymer                                                           2  Jibaro                                                                              Biopolymer                                                                           1,298  Dynamic                                                                              77/23  <5 min.                                                                            1 in. Inverted in                            Other Than                             pipe loop*                             Xanthan                                                              __________________________________________________________________________     *Viscosity and ΔP across pipe loop increased rapidly to limits of       pump capacity.                                                           

EXAMPLE XXIV

The oil samples used for these investigations were Manatokan crude. Theaqueous phase was brine having a pH of greater than about 5.0. Thesurface active agents used in the testing series were the followingethoxylated nonyl phenols (NP): T-DET-N-20 (i.e. NP 20), T-DET-N-40(i.e. NP 40), and T-DET-N-100 (i.e. NP 100). Each of the ethoxylated NPemulsifying agent(s) includes a collection of ethoxylated NP compoundswherein the number of --CH₂ --CH₂ --O--_(y) repeat units or segments canvary from where y may have a value ranging from about 4 to about 1000."T-DET" is a trademark of the Thompson-Hayward Chemical Corp., KansasCity, Mo. The respective ethoxylated nonyl phenols were purified ofglycols by polyglycol separation. The emulsifying composition(s) wasmixed with the Manatokan crude at a temperature of 125° F.±25° F. Anoil-in-water (or oil-in-aqueous phase) emulsion was formed with theemulsifying-crude mixture by positioning the mixture in a rotor statormixer. Mixing energies were 2,000 rpm to 4,000 rpm for 40 secs. to 80secs. The oil-in-water emulsion(s) produced contained from about 15percent to about 60 percent by weight brine. The following Table VIIIdiscloses shear life (which is the measure of emulsion stability) thatwas detected for the various mixtures of NP 20/NP 40/NP100:

                                      TABLE VIII                                  __________________________________________________________________________                                  Estimated Quantity                                                            in % by Wt. of                                                                NP Compounds in                                 Mixture of NP20/NP40/NP100                                                                   Weight Average Mixture Having                                                                          Emulsion                              (in % by wt. in mixture)                                                                     Molecular Weight                                                                       Dispersity                                                                          a M.W. Between                                                                          Shear                                 NP20 NP40 NP100                                                                              of Mixture*                                                                            of Mixture*                                                                         1966 and 9188                                                                           Stability                             __________________________________________________________________________    25%  25%  50%  2,301    1.77  51%       49 mins.                              25%  50%  25%  2,089    1.69  37%       38 mins.                              50%  25%  25%  1,946    1.91  41%       29 mins.                              __________________________________________________________________________     *Molecular weights, weight average molecular weight, and dispersity of        mixture of emulsifying agent(s) were obtained by gel permeation               chromatography. Each ethoxylated NP emulsifying agent comprises a             collection of ethoxylated nonyl phenol compounds wherein the number of        (--CH.sub.2 --CH.sub.2 --O)-- repeat units or segments may vary from abou     4 to about 1000. A molecular weight distribution for the total collection     of all ethoxylated nonyl phenol compounds within the mixture of               ethoxylated NP emulsifying agent(s) is obtained by the gel permeation         chromatography. From this molecular weight distribution, the following        parameters are determined: (a) weight average molecular weight of the         mixture, (b) estimated quantity in % by weight of NP compounds in mixture     having a molecular weight between 1966 and 9188, and (c) dispersity of th     mixture of ethoxylated NP emulsifying agent(s).                          

Assuming that for commercial purposes an emulsion shear stability ofless than 40 mins. is unacceptable, the only emulsifying mixture inTable VIII producing an oil-in-water emulsion with an acceptable (i.e.commercially acceptable) emulsion shear stability is the 25/25/50mixture of NP 20/NP 40/NP 100. The weight average molecular weight forthis mixture was 2301 (which was between 1966 and 9188) and thedispersity of 1.77 was between 1.0 and 5.0. Furthermore, the estimatedquantity in % by weight of NP compounds in the 25/25/50 surfactantmixture having a molecular weight of between 1966 and 9188 was 51% byweight (which is greater than at least 50% by weight). The 50/25/25mixture did not produce an acceptable oil-in-water emulsion having anemulsion shear stability greater than or equal to 40 mins. because theweight average molecular weight of the mixture was 1946 (which is notbetween 1966 and 9188), and further because the estimated quantity in %by weight of NP compounds in the 50/25/25 surfactant mixture having amolecular weight of 1966 to 9188 was 41% by weight (which is less thanat least 50% by weight). The 25/50/25 mixture also did not produce anacceptable oil-in-water emulsion because the estimated quantity in % byweight of NP compounds in the 25/50/25 surfactant mixture having amolecular weight of 1966 to 9188 was 37% by weight, which is less than50% by weight. Had this estimated quantity in by weight been 50% byweight or greater, an acceptable oil-in-water emulsion would have beenformed.

EXAMPLE XXV

The oil or hydrocarbon samples utilized for these investigations wereManatokan crude. The water or aqueous phase was brine with a pH ofgreater than about 4.5. The emulsifying agents were the followingethoxylated nonyl phenols (NP): T-DET-N-40 (i.e. NP 40), T-DET-N-100(i.e. NP 100), and T-DET-N-150 (i.e. NP 150). Similar to the emulsifyingagent(s) in Example XXIV, each of these ethoxylated NP emulsifyingagent(s) includes a collection of ethoxylated nonyl phenol compoundswherein the number of --CH₂ --CH₂ --O--_(y) repeat units of segments canvary from where y may have a value of from about 4 to about 1000. Allemulsifying agent(s) were purified of glycols by polyglycol separation.From about 100 ppm to about 5000 ppm (typically about 750 ppm) ofemulsifying agent(s) by weight of Manatokan crude were mixed with eachother in various proportions by weight and with the aqueous phase brineto form emulsifying composition(s). The Manatokan crude was mixed withthe emulsifying composition(s) at a temperature of 135° F.± about 35° F.An oil-in-water (or crude-in-water) emulsion was formed with theemulsifying-crude mixture by positioning the mixture in a rotor statormixer. Mixing energies were 2,000 rpm to 4,000 rpm (typically 3,000 rpm)for 30 secs. to 90 secs. The oil-in-water emulsion(s) produced containedfrom about 15 percent to about 60 percent by weight aqueous phase (i.e.brine). The following Table IX discloses shear life (or emulsionstability) that was measured or discovered for the various mixtures ofNP 40/NP 100/NP 150:

                                      TABLE IX                                    __________________________________________________________________________                                   Estimated Quantity                                                            in % by Wt. of                                                                NP Compounds in                                Mixture of NP40/NP100/NP150                                                                   Weight Average Mixture Having                                                                          Emulsion                             (in % by wt. in mixture)                                                                      Molecular Weight                                                                       Dispersity                                                                          a M.W. Between                                                                          Shear                                NP40 NP100 NP150                                                                              of Mixture*                                                                            of Mixture*                                                                         1966 and 9188                                                                           Stability                            __________________________________________________________________________    25%  25%   50%  5,629    1.27  83%       83 mins.                             25%  50%   25%  5,153    1.25  87%       87 mins.                             50%  25%   25%  4,909    1.27  80%       65 mins.                             __________________________________________________________________________     *Molecular weights, weight average molecular weight, and dispersity of        mixture of emulsifying agent(s) were obtained by gel permeation               chromatography. Each ethoxylated NP emulsifying agent comprises a             collection of ethoxylated nonyl phenol compounds wherein the number of        (--CH.sub.2 --CH.sub.2 --O)-- repeat units or segments may vary from abou     4 to about 1000. A molecular weight distribution for the total collection     of all ethoxylated nonyl phenol compounds within the mixture of               ethoxylated NP emulsifying agent(s) is obtained by the gel permeation         chromatography. From this molecular weight distribution, the following        parameters are determined: (a) weight average molecular weight of the         mixture, (b) estimated quantity in % by weight of NP compounds in mixture     having a molecular weight between 1966 and 9188, and (c) dispersity of th     mixture of ethoxylated NP emulsifying agent(s).                          

All emulsifying mixtures produced a commercially acceptable (i.e. above40 mins.) oil-in-water emulsion because for each mixture, the weightaverage molecular weights were between 1966 and 9188, the dispersitieswere between 1.0 and 5.0, and the % by weight of NP compounds (in theemulsifying agent mixture) having a molecular weight between 1966 and9188 was at least 50% by weight. Had any particular emulsifying mixturehad a dispersity greater than about 5.0 and/or a weight averagemolecular weight outside of the range of 1966 to 9188 and/or less thanabout 50% by weight of the NP compounds in the emulsifying agent mixturehaving a molecular weight of 1966 to 9188, the formed oil-in-wateremulsion produced therefrom would not have been commercially acceptable.

EXAMPLE XXVI

The oil samples are Manatokan crude. The aqueous phase is brine with apH above 4.0. The emulsifying agent(s) are NP 30 (i.e. T-DET-N-30) andNP 270 (i.e. T-DET-N-270). Each NP emulsifying agent comprises a groupor collection of ethoxylated nonyl phenol compounds wherein the (CH₂--CH₂ --O)_(y) repeat units range from where y has a value of about 4 toabout 1000. NP30 and/or NP 270 has at least one ethoxylated alkylphenolcompound having the general formula: ##STR22## where y is greater than100, more typically greater than 100 but less than 1000, and theethoxylated alkylphenol compound preferably comprises at least 1% byweight (more preferably 1% to 90% by weight) of the entire mixture of NP30 and NP 270 together. The emulsifying agent(s) are purified fromglycols. From 100 ppm to 5000 ppm of emulsifying agent(s) by weight ofManatokan crude are mixed with each other in an 80% NP 30/20% NP 270proportion by weight and with the aqueous phase brine to formemulsifying composition(s). The Manatokan crude is mixed with theemulsifying composition(s) at a temperature of 110° F.±about 10° F. Themixture is placed in a rotor stator mixer and the latter is energized ata mixing energy between 2,000 rpm to 4,000 rpm for 40 to 60 secs. toform or produce oil-in-water emulsion(s) containing from about 15percent to about 60 percent by weight aqueous phase (i.e. brine). Thefollowing Table X discloses emulsion stability that is found for the80%/20% by weight mixture of NP 270:

                                      TABLE X                                     __________________________________________________________________________                               Estimated Quantity                                                            in % by Wt. of                                                                NP Compounds in                                    Mixture of NP30/NP270                                                                     Weight Average Mixture Having                                                                          Emulsion                                 (in % by wt. in mixture                                                                   Molecular Weight                                                                       Dispersity                                                                          a M.W. Between                                                                          Shear                                    NP30  NP270 of Mixture*                                                                            of Mixture*                                                                         1966 and 9188                                                                           Stability                                __________________________________________________________________________    80%   20%   8,538    2.34  0%        Less than                                                                     25 mins.                                 __________________________________________________________________________     *Molecular weights, weight average molecular weight, and dispersity of        mixture of emulsifying agent(s) were obtained by gel permeation               chromatography. Each ethoxylated NP emulsifying agent comprises a             collection of ethoxylated nonyl phenol compounds wherein the number of        (--CH.sub.2 --CH.sub.2 --O)-- repeat units or segments may vary from abou     4 to about 1000. A molecular weight distribution for the total collection     of all ethoxylated nonyl phenol compounds within the mixture of               ethoxylated NP emulsifying agent(s) is obtained by the gel permeation         chromatography. From this molecular weight distribution, the following        parameters are determined: (a) weight average molecular weight of the         mixture, (b) estimated quantity in % by weight of NP compounds in mixture     having a molecular weight between 1966 and 9188, and (c) dispersity of th     mixture of ethoxylated NP emulsifying agent(s).                          

The emulsifying mixture in this Example produces a commerciallyunacceptable oil-in-water emulsion. The reason for the unacceptableoil-in-water emulsion is that the estimated quantity in % by weight ofNP compounds in the emulsifying mixture having a molecular weight of1966 to 9188 is 0%.

EXAMPLE XXVII

Repeat Example XXVI but for 60% by weight of NP 15 and 40% by weight NP100 and find the following: a weight average molecular weight of 3790for the 60% NP 15/40% NP 100 mixture, a dispersity of 1.59, and 40% byweight as the estimated quantity of NP compounds in the 60% NP 15/40% NP100 mixture having a molecular weight between 1966 and 9188, and anemulsion shear stability of 25 mins. or less. The emulsion shearstability is unacceptable because of the 40% by weight of the estimatedquantity of NP compounds in the 60% NP 15/40% NP 100 mixture.

EXAMPLE XXVIII

Repeat Example XXVI but for 45% by weight NP 10 and 55% by weight NP 50and find the following: a weight average molecular weight of 1628 forthe 45% NP 10/55% NP 50 mixture, a dispersity of 1.29, and 55% by weightas the estimated quantity of NP compounds in the 45% NP 10/55% NP 50mixture having a molecular weight between 1966 and 9188, and an emulsionshear stability of less than 10 mins. The emulsion shear stability isunacceptable because of the 1628 weight average molecular weight.

EXAMPLE XXIX

Repeat Example XXVI but for 60% by weight NP 150 and 40% by weight NP300 and find the following: a weight average molecular weight of 10,565for the 60% NP 150/40% NP 300 mixture, a dispersity of 1.12, and 60% byweight as the estimated quantity of NP compounds in the 60% NP 150/40%NP 300 mixture having a molecular weight between 1966 and 9188, and anemulsion shear stability of less than 35 mins. The emulsion shearstability is unacceptable because of the 10,565 weight average molecularweight.

EXAMPLE XXX

Repeat Example XXVI but for 90% by weight NP 100 and 10% by weight NP1000 and find the following: a weight average molecular weight of 15,900of the 90% NP 100/10% NP 1000 mixture, a dispersity of 2.19, and 90% byweight as the estimated quantity of NP compounds in the 90% NP 100/10%NP 1000 mixture having a molecular weight between 1966 and 9188, and anemulsion shear stability of less than 35 mins. The emulsion shearstability is unacceptable because of the 15,900 weight average molecularweight.

EXAMPLE XXXI

The oil samples for these investigations are Manatokan crude. Theaqueous phase is brine having a pH of greater than about 5.0. Thesurface active agents in the testing series are the followingethoxylated nonyl phenol compounds: T-DET-N-10.5 (i.e. NP 10.5),T-DET-N-20 (i.e. NP 20), and T-DET-N-30 (i.e. NP 30). Each of theethoxylated NP emulsifying agent(s) includes a collection of ethoxylatedNP molecules wherein the number of --CH₂ --CH₂ --O--_(y) repeat units orsegments can vary from where y may have a value ranging from about 4 toabout 200. "T-DET" is a trademark of the Thompson-Hayward ChemicalCorp., Kansas City, Mo. The respective ethoxylated nonyl phenols arepurified of polyethylene glycol by polyethylene glycol separation. Theemulsifying composition(s) is mixed with the Manatokan crude at atemperature of 125° F.±25° F. An oil-in-water (or oil-in-aqueous phase)emulsion is formed in some instances with the emulsifying-crude mixtureby positioning and agitating the mixture in a rotor stator mixer. Mixingenergies are 500 rpm to 4,000 rpm (typically 1,000 rpm) for 30 secs. to90 secs. The oil-in-water emulsion(s) that are produced contain fromabout 15 percent to about 60 percent by weight brine. The followingTable XI discloses time to form a water continuous emulsion and shearlife of the water continuous emulsion after formation (which is themeasure of emulsion stability) that is detected for the various mixturesof NP 10.5/NP 20/NP 30:

                                      TABLE XI                                    __________________________________________________________________________    LOW TEMP: VARIATION                                                           ABOUT NP-20: MID RANGE                                                                                       Estimated Quantity                                                            in % by Wt. of                                                                NP Compounds in                                Mixture of NP10.5/NP20/NP30                                                                   Weight Average Mixture Having                                                                          Time to Form                                                                             Emulsion                  (in % by wt. in mixture)                                                                      Molecular Weight                                                                       Dispersity                                                                          a M.W. Between                                                                          A Water Continuous                                                                       Shear                     NP10.5                                                                             NP20  NP30 of Mixture                                                                             of Mixture*                                                                         558 and 2504                                                                            Emulsion   Stability                 __________________________________________________________________________    20%  20%   60%  1,430    2.50  42%       32 secs.   38 mins.                  20%  60%   20%  1,220    1.70  85%       11 secs.   49 mins.                  60%  20%   20%  1,100    3.00  37%       Did not form                                                                             Did not                                                                       form                      __________________________________________________________________________     *Molecular weights, dispersity and estimated quantity in % by wt. of NP       compounds in mixture having a M.W. between 558 and 2504 are obtained by       structural considerations based on a Gaussian (normal) distribution           specified for each designated emulsifying agent.                         

Assuming that for commercial purposes a period of time greater thanabout 20 secs. to form a water continuous emulsion is unacceptable and awater continuous emulsion shear stability of less than 40 mins. isunacceptable, the only emulsifying mixture in Table XI producing anoil-in-water emulsion within an acceptable period of time and with anacceptable (i.e. commercially acceptable) emulsion shear stability isthe 20/60/20 mixture of NP 10.5/NP 20/NP 30. The weight averagemolecular weight for this mixture is 1220 (which is between 558 and2405) and the dispersity of 1.70 is between 1.0 and 5.0. Furthermore,the estimated quantity in percent by weight of NP compounds in the20/60/20 surfactant mixture having a molecular weight of between 558 and2504 is 85% by weight (which is greater than at least 50% by weight).The 60/20/20 mixture did not produce within an acceptable period of timeof less than about 20 secs. an acceptable oil-in-water emulsion havingan emulsion shear stability greater than or equal to 40 mins. becausethe estimated quantity in percent by weight of NP compounds in the60/20/20 surfactant mixture having a molecular weight 558 to 2504 is 37%by weight (which is less than at least 50% by weight). The 20/20/60mixture also did not produce an acceptable oil-in-water emulsion becausethe estimated quantity in percent by weight of NP compounds in the20/20/60 surfactant mixture having a molecular weight of 558 to 2504 is42% by weight, which is less than 50% by weight. If this estimatedquantity in percent by weight is 50% by weight or greater, an acceptableoil-in-water emulsion would be formed within an acceptable period oftime.

EXAMPLE XXXII

The oil or hydrocarbon samples for these investigations are Manatokancrude. The water or aqueous phase is brine with a pH of greater thanabout 4.5. The emulsifying agents are the following ethoxylated nonylphenol compounds: T-DET-N-20 (i.e. NP 20), T-DET-N-40 (i.e. NP 40), andT-DET-N-70 (i.e. NP 70). Similar to the emulsifying agent(s) in ExampleXXXI, each of these ethoxylated NP emulsifying agent(s) includes acollection of ethoxylated nonyl phenol molecules wherein the number of--CH₂ CH₂ --O--_(y) repeat units of segments can vary from where y mayhave a value of from about 4 to about 200. All emulsifying agent(s) arepurified of polyethylene glycol by polyethylene glycol separation. Fromabout 100 ppm to about 5,000 ppm (typically about 750 ppm) ofemulsifying agent(s) by weight of Manatokan crude are mixed with eachother in various proportions by weight and with the aqueous phase brineto form emulsifying composition(s). The Manatokan crude is mixed withthe emulsifying composition(s) at a temperature of 135 F.± about 25° F.An oil-in-water (or crude-in-water) emulsion is formed in some instanceswith the emulsifying-crude mixture by positioning and agitating themixture in a rotor stator mixer. Mixing energies are 500 rpm to 4,000rpm (typically 1,000 rpm) for 30 secs. to 90 secs. The oil-in-wateremulsion(s) that are produced contain from about 15 percent to about 60percent by weight aqueous phase (i.e. brine). The following Table XIIdiscloses time to form a water continuous emulsion and shear life of thewater continuous emulsion after formation (or emulsion stability) thatis measured or discovered for the various mixtures of NP 20/NP 40/NP 70:

                                      TABLE XII                                   __________________________________________________________________________    LOW TEMP: VARIATION                                                           ABOUT NP-20: HIGH RANGE                                                                                        Estimated Quantity                                                            in % by Wt. of                                                                NP Compounds in                              Mixture of NP20/NP40/NP70                                                                      Weight Average  Mixture Having                                                                          Time to Form                                                                              Emulsion               (in % by wt. in mixture)                                                                       Molecular Weight                                                                       Dispersity                                                                           a M.W. Between                                                                          A Water Continuous                                                                        Shear                  NP20  NP40 NP70  of Mixture                                                                             of Mixture*                                                                          558 and 2504                                                                            Emulsion    Stability              __________________________________________________________________________    20%   20%  60%   3,020    1.20   40%       27 secs.    35 mins.               20%   60%  20%   2,363    1.30   47%       No emulsion No emulsion            60%   20%  20%   2,230    1.35   70%       14 secs.    45                     __________________________________________________________________________                                                           mins.                   *Molecular weights, dispersity and estimated quantity in % by wt. of NP       compounds in mixture having a M.W. between 558 and 2504 are obtained by       structural considerations based on a Gaussian (normal) distribution           specified for each designated emulsifying agent.                         

Assuming that for commercial purposes a period of time greater thanabout 20 secs. to form a water continuous emulsion is unacceptable and awater continuous emulsion shear stability of less than 40 mins. isunacceptable, the only emulsifying mixture in Table XII producing anoil-in-water emulsion within an acceptable period of time and with anacceptable (i.e. commercially acceptable) emulsion shear stability isthe 60/20/20 mixture of NP 20/NP 40/NP 70. The weight average molecularweight for this mixture is 2230 (which is between 558 and 2504) and thedispersity of 1.20 is between 1.0 and 5.0. Furthermore, the estimatedquantity in percent by weight of NP compounds in the 60/20/20 surfactantmixture having a molecular weight of between 558 and 2504 is 70% byweight (which is greater than at least 50% by weight). The 20/20/60mixture did not produce within an acceptable period of time of less thanabout 20 secs. an acceptable oil-in-water emulsion having an emulsionshear stability greater than or equal to 40 mins. because the weightaverage molecular weight of the mixture is 3020 (which is not between558 and 2504), and furthermore because the estimated quantity in percentby weight of NP compounds in the 20/20/60 surfactant mixture having amolecular weight of 558 to 2504 is 40% by weight (which is less than atleast 50% by weight). The 20/60/20 mixture also did not produce anacceptable oil-in-water emulsion because the estimated quantity inpercent by weight of NP compounds in the 20/60/20 surfactant mixturehaving a molecular weight of 558 to 2504 is 47% by weight, which is lessthan 50% by weight. If this estimated quantity in percent by weight is50% by weight or greater, an acceptable oil-in-water emulsion would beformed within an acceptable period of time.

EXAMPLE XXXIII

The oil samples for these investigations are Manatokan crude. Theaqueous phase is brine having a pH of greater than about 5.0. Thesurface active agents in the testing series are the followingethoxylated nonyl phenol compounds: T-DET-N-5 (i.e. NP 5), T-DET-N-10.5(i.e. NP 10.5), and T-DET-N-20 (i.e. NP 20). Each of the ethoxylated NPemulsifying agent(s) includes a collection of ethoxylated NP moleculeswherein the number of --CH₂ --CH₂ --O--_(y) repeat units or segments canvary from where y may have a value ranging from about 4 to about 200.The respective ethoxylated nonyl phenols are purified of polyethyleneglycol by polyethylene glycol separation. The emulsifying composition(s)are mixed with the Manatokan crude at a temperature of 125° F.±25° F. Anoil-in-water (or oil-in-aqueous phase) emulsion is formed with theemulsifying-crude mixture by positioning the mixture in a rotor statormixer. Mixing energies are 520 rpm to 4,000 rpm (typically 1,000 rpm)for 30 secs. to 90 secs. The oil-in-water emulsion(s) that are producedcontain from about 15 percent to about 60 percent by weight brine. Thefollowing Table XIII discloses time to form a water continuous shearlife of the water continuous emulsion after formation (which is themeasure of emulsion stability) that is detected for the various mixturesof NP 5/NP 10.5/NP 20:

                                      TABLE XIII                                  __________________________________________________________________________    LOW TEMP: VARIATION                                                           ABOUT NP-20: LOW RANGE                                                                                      Estimated Quantity                                                            in % by Wt. of                                                                NP Compounds in                                 Mixture of NP5/NP10.5/NP20                                                                   Weight Average Mixture Having                                                                          Time to Form                                                                             Emulsion                   (in % by wt. in mixture)                                                                     Molecular Weight                                                                       Dispersity                                                                          a M.W. Between                                                                          A Water Continuous                                                                       Shear                      NP5  NP10.5                                                                             NP20 of Mixture                                                                             of Mixture*                                                                         558 and 2504                                                                            Emulsion   Stability                  __________________________________________________________________________    20%  20%  60%  1,010    1.16  77.6%      5 secs.   42 mins.                   20%  60%  20%  750      1.24  45.0%     11 secs.   36 mins.                   60%  20%  20%  744      1.25  39.1%     16 secs.   30 mins.                   __________________________________________________________________________     *Molecular weights, dispersity and estimated quantity in % by wt. of NP       compounds in mixture having a M.W. between 558 and 2504 are obtained by       structural considerations based on a Gaussian (normal) distribution           specified for each designated emulsifying agent.                         

Assuming that for commercial purposes a period of time greater thanabout 20 secs. to form a water continuous emulsion is unacceptable and awater continuous emulsion shear stability of less than 40 mins. isunacceptable, the only emulsifying mixture in Table XIII producing anoil-in-water emulsion within an acceptable period of time and with anacceptable (i.e. commercially acceptable) emulsion shear stability isthe 20/20/60 mixture of NP 5/NP 10.5/NP 20. The weight average molecularweight for this mixture is 1010 (which is between 558 and 2504) and thedispersity of 1.16 is between 1.0 and 5.0. Furthermore, the estimatedquantity in percent by weight of NP compounds in the 20/20/60 surfactantmixture having a molecular weight of between 558 and 2504 is 77.6% byweight (which is greater than at least 50% by weight). The 60/20,20,mixture did not produce an acceptable oil-in-water emulsion having anemulsion shear stability greater than or equal to 40 mins. because theestimated quantity in percent by weight of NP compounds in the 60/20/20surfactant mixture having a molecular weight of 558 to 2504 is 39.1% byweight (which is less than at least 50% by weight). The 20/60/20 mixturealso did not produce an acceptable oil-in-water emulsion because theestimated quantity in percent by weight of NP compounds in the 20/60/20surfactant mixture having a molecular weight of 558 to 2504 is 45% byweight, which is less than 50% by weight. If this estimated quantity inpercent by weight is 50% by weight or greater, an acceptableoil-in-water emulsion would be formed.

EXAMPLE XXXIV

Repeat Example XXXI with the emulsifying composition(s) mixed with theManatokan crude at a temperature of about 185° F., and find that the20/60/20 mixture of NP 10.5/NP 20/NP 30 did not produce an oil-in-wateremulsion within a commercially acceptable period of time and with acommercially acceptable emulsion shear stability because the emulsifyingcomposition(s)-Manatokan crude had a temperature above about 170° F.

EXAMPLE XXXV

Repeat Example XXXII with the emulsifying composition(s) mixed with theManatokan crude at a temperature of about 180° F., and find that the60/20/20 mixture of NP 20/NP 40/NP 70 did not produce an oil-in-wateremulsion within a commercially acceptable period of time and with acommercially acceptable emulsion shear stability because the emulsifyingcompositions-Manatokan crude had a temperature above about 170° F.

EXAMPLE XXXVI

Repeat Example XXXIII with the emulsifying composition(s) mixed with theManatokan crude at a temperature of about 195° F., and find that the20/20/60 mixture of NP 5/NP 10.5/NP 20 did not produce an oil-in-wateremulsion within a commercially acceptable period of time and with acommercially acceptable emulsion shear stability because the emulsifyingcomposition(s)-Manatokan crude had a temperature above about 170° F.

EXAMPLE XXXVII

The oil samples are Manatokan crude. The aqueous phase is brine with apH above 4.0. The emulsifying agent(s) comprise 75% by weightethoxylated nonyl phenols (NP) agents and 25% by weight of at least oneethoxylated alkylphenol (EA) agent having the general formula: ##STR23##where n is an integer having a value of from 9 to 14 (inclusive) and yis an integer having a value of from 4 to 300 (inclusive). The EA agenthas a molecular weight distribution with a dispersity of from about 1.0to about 5.0 and with a weight average molecular weight of from about2434 to about 4264; and at least about 50% by weight of the EA agentcomprises at least one ethoxylated alkylphenol compound having amolecular weight of from about 2434 to about 4264. The NP agents are thefollowing: T-DET-N 20 (i.e. NP 20), T-DET-N 40 (i.e. NP 40), and T-DET-N100 (i.e. NP 100). Each of the ethoxylated NP agents includes acollection of ethoxylated NP compounds wherein the number of --CH₂ --CH₂--O--_(y) repeat units or segments can vary from where y may have avalue ranging from about 4 to about 200. All of the respectiveemulsifying agents are purified of glycols by polyglycol separation.From about 100 ppm to about 5,000 ppm (typically about 750 ppm) of theemulsifying agent(s) by weight of Manatokan crude are mixed with eachother in various proportions by weight and with the aqueous phase brineto form emulsifying composition(s). The Manatokan crude is mixed withthe emulsifying composition(s) at a temperature of 190° F.±5° F. Anoil-in-water (or oil-in-aqueous phase) emulsion is formed with theemulsifying composition-crude mixture by positioning the mixture in arotor stator mixer. Mixing energies are 2,000 rpm to 4,000 rpm(typically 3,000 rpm) for 30 secs to 90 secs. The oil-in-wateremulsion(s) that are produced contain from about 15% to about 60% byweight aqueous phase (i.e. brine). The following Table XIV disclosestime to form a water continuous emulsion and shear life (or emulsionstability) that is measured or discovered for the various mixtures of NP20/NP 40/NP 100 in combination with the 25% by weight of the EA agent:

                                      TABLE XIV                                   __________________________________________________________________________                                             Estimated Quantity                                                            in % by Wt. of                       EA AGENT Mixture of NP20/NP40/NP100      NP Compounds in                                                                         Time to                    (in % by wt. in                                                                        (in % by wt. in                                                                              Weight Average   NP Mixture Having                                                                       Form                                                                                 Emulsion            NP/EA agent                                                                            NP/EA agent mixture)                                                                         Molecular Weight                                                                       Dispersity of                                                                         a M.W. Between                                                                          Continuous                                                                           Shear               mixture) NP20 NP40 NP100                                                                              of NP Mixture*                                                                         NP Mixture*                                                                           558 and 1582                                                                            Emulsion                                                                             Stability           __________________________________________________________________________    25%      45%  15%  15%  1,284    1.52    67.0%      7 secs.                                                                             73 mins.            25%      15%  45%  15%  1,814    1.32    37.0%     34 secs.                                                                             28 mins.            25%      15%  15%  45%  2,753    1.25    22.1%     48 secs.                                                                             18                  __________________________________________________________________________                                                              mins.                *Molecular weights, weight average molecular weight, and dispersity of        mixture of NP emulsifying agent(s) are obtained by structure. Each            ethoxylated NP emulsifying agent comprises a collection of ethoxylated        nonyl phenol compounds wherein the number of (--CH.sub.2 --CH.sub.2 --O)-     repeat units or segments may vary from about 4 to about 200. A molecular      weight distribution for the total collection of all ethoxylated nonyl         phenol compounds within the mixture of ethoxylated NP emulsifying agent(s     is obtained by structure. From this molecular weight distribution, the        following parameters are determined: (a) weight average molecular weight      of mixture, (b) estimated quantity in % by weight of NP compounds in          mixture having a molecular weight between 558 and 1582, and (c) dispersit     of the mixture of ethoxylated NP emulsifying agent(s).                   

Assuming that for commercial purposes a period of time greater thanabout 20 secs. to form a water continuous emulsion is unacceptable and awater continuous emulsion shear stability of less than 40 mins. isunacceptable, the only emulsifying NP/EA agent mixture in Table XIVproducing an oil-in-water emulsion within an acceptable period of timeand with a commercially acceptable emulsion shear stability is the45/15/15 mixture of NP 20/NP 40/NP 100 in combination with 25% by weightEA agent. The weight average molecular weight for the NP mixture is 1284(which is between 558 and 1582) and the dispersity of 1.52 is between1.0 and 5.0. Furthermore, the estimated quantity in % by weight of NPcompounds in the NP mixture having a molecular weight of between 558 and1582 is 67% by weight (which is greater than at least 50% by weight).The 15/45/15 mixture of NP 20/NP 40/NP 100 in combination with 25% byweight of the EA agent did not produce within an acceptable period oftime of less than about 20 secs. an acceptable oil-in-water emulsionhaving an emulsion shear stability greater than or equal to 40 mins.because the estimated quantity in percent by weight of NP compounds inthe NP mixture having a molecular weight of 558 to 1582 is 37% by weight(which is less than at least 50% by weight). If this estimated quantityin percent by weight is 50% by weight or greater, an acceptableoil-in-water emulsion would be formed within an acceptable period oftime. The 15/15/45 mixture of NP 20/NP 40/NP 100 in combination with 25%by weight of the EA agent did not produce an acceptable oil-in-wateremulsion because the estimated quantity in percent by weight of NPcompounds in the 15/15/45 Np mixture having a molecular weight of 558 to1582 is 22.1% by weight (which is less than at least 50% by weight), andfurther because the weight average molecular weight of the mixture is2753 (which is not between 558 and 1582). If this estimated quantity inpercent by weight is 50% by weight or greater and if the weight averagemolecular weight is between 558 and 1582, an acceptable oil-in-wateremulsion would be formed within an acceptable period of time.

EXAMPLE XXXVIII

Repeat Example XXXVII where n in the general formula: ##STR24## is 8 orless and find that an acceptable oil-in-water emulsion is not formedand/or is not formed within an acceptable period of time.

EXAMPLE XXXIX

Repeat Example XXXVII where n in the general formula: ##STR25## is 15 orgreater and find that an acceptable oil-in-water emulsion is not formedand/or is not formed within an acceptable period of time.

EXAMPLE XXXX

Repeat Example XXXVII where the percent by weight of the EA agent in theNP/EA agent mixture is decreased to below 15% by weight and the percentby weight of the respective NP compounds (i.e. NP 20, NP 40, and NP 100)in the NP/EA agent mixture is varied and/or adjusted accordingly suchthat the weight average molecular weight of the NP mixture is 558 to1582, dispersity of the NP mixture is 1.0 to 5.0, and the estimatedquantity in percent by weight of NP compounds in the NP mixture having amolecular weight between 558 and 1582 is at least 50% by weight, andfind that an acceptable oil-in-water emulsion is not formed and/or isnot formed within an acceptable period of time.

EXAMPLE XXXXI

Repeat Example XXXX where the percent by weight of the EA agent in theNP/EA agent mixture is increased above 40% by weight and find similarresults.

EXAMPLE XXXXII

The oil samples are PCEJ crude. The aqueous phase is brine with a pHabove 4.5. The emulsifying agent(s) comprise 75% by weight of an NP 20agent and 25% of three ethoxylated alkylphenol agents with each of theagents having the general formula: ##STR26## wherein for one agent(hereinafter identified as DD 20) y equals 20 and is a mean of a normal(Gaussian) distribution curve; for a second agent (hereinafteridentified as DD 70) y equals 70 and is a mean of a normal (Gaussian)distribution curve; and for the third agent (hereinafter identified asDD 150) y equals 150 and is also a mean of a normal (Gaussian)distribution curve. The mixture of DD 20/DD 70/DD 100 will be referredto collectively hereafter as the DD mixture. Each of the DD agentsincludes a collection of ethoxylated dodecyl compounds wherein thenumber of --CH₂ --CH₂ --O--_(y) repeat units or segments can vary fromwhere x may have a value ranging from about 4 to about 300. The NP 20agent has a molecular weight distribution with a dispersity of fromabout 1.0 to about 5.0 and with a weight average molecular weight offrom about 558 to about 1582; and at least about 50% by weight of the NP20 agent comprises at least one ethoxylated nonyl phenol compound havinga molecular weight of from about 558 to about 1582. All of therespective emulsifying agents are purified of polyethylene glycols bypolyethylene glycol separation. From about 100 ppm to about 5,000 ppm(typically about 750 ppm) of the emulsifying agent(s) by weight of PCEJcrude are mixed with each other in various proportions by weight andwith the aqueous phase brine to form emulsifying composition(s). ThePCEJ crude is mixed with the emulsifying composition(s) at a temperatureof 200° F.±5° F. An oil-in-water (or oil-in-aqueous phase) emulsion isformed with the emulsifying composition-crude mixture by positioning,placing or passing the mixture through a rotor stator mixer. Mixingenergies are 2,000 rpm to 4,000 rpm (typically 3,000 rpm) for 30 secs.to 90 secs. The oil-in-water emulsion(s) that are produced contain fromabout 15 percent to about 60 percent by weight aqueous phase (i.e.brine). The following Table XV discloses time to form a water continuousemulsion and shear life (or emulsion stability) that is measured ordiscovered for the various mixtures of DD 20/DD 70/DD 150 in combinationwith the 75% by weight of the NP 20 agent:

                                      TABLE XV                                    __________________________________________________________________________                                             Estimated Quantity                                                            in % by Wt. of                       NP20 AGENT                                                                             Mixture of DD20/DD40/DD150      NP Compounds in                                                                         Time to                    (in % by wt. in                                                                        (in % by wt. in Weight Average  NP Mixture Having                                                                       Form                                                                                 Emulsion            NP20 agent                                                                             NP/EA agent mixture)                                                                          Molecular Weight                                                                       Dispersity of                                                                        a M.W. Between                                                                          Continuous                                                                           Shear               mixture) DD20 DD70  DD150                                                                              of DD Mixture*                                                                         DD Mixture*                                                                          2434 and 4264                                                                           Emulsion                                                                             Stability           __________________________________________________________________________    75%      15%  5%    5%   3,912    1.71   16.4%     24 secs.                                                                             35 mins.            75%      5%   15%   5%   4,171    1.30   55.0%      5 secs.                                                                             71 mins.            75%      5%   5%    15%  6,281    1.25   24.0%     42 secs.                                                                             16                  __________________________________________________________________________                                                              mins.                *Molecular weights, weight average molecular weight, and dispersity of        mixture of DD emulsifying agent(s) are obtained by structure. Each            ethoxylated DD emulsifying agent comprises a collection of ethoxylated DD     phenol compounds wherein the number of (--CH.sub.2 --CH.sub.2 --O)--          repeat units or segments may vary from about 4 to about 300. A molecular      weight distribution for the total collection of all ethoxylated DD phenol     compounds within the mixture of ethoxylated DD emulsifying agent(s) is        obtained by structure. From this molecular weight distribution, the           following parameters are determined: (a) weight average molecular weight      of mixture, (b) estimated quantity in % by weight of DD compounds in          mixture having a molecular weight between 2434 and 4264, and (c)              dispersity of the mixture of ethoxylated DD emulsifying agent(s).        

Assuming that for commercial purposes a period of time greater thanabout 20 secs. to form a water continuous emulsion is unacceptable and awater continuous emulsion shear stability of less than 40 mins. isunacceptable, the only emulsifying DD/NP 20 mixture in Table XVproducing an oil-in-water emulsion within an acceptable period of timeand with a commercially acceptable emulsion shear stability is the5/15/5 mixture of DD 20/DD 70/DD 150 in combination with 75% by weightNP 20 agent. The weight average molecular weight for the DD mixture is4171 (which is between 2434 and 4264) and the dispersity of 1.30 isbetween 1.0 and 5.0. Furthermore, the estimated quantity in percent byweight of DD compounds in the DD mixture having a molecular weight ofbetween 2434 and 4264 is 55% by weight (which is greater than at least50% by weight). The 15/5/5 mixture of DD 20/DD 70/DD 150 in combinationwith 75% by weight percent of the NP 20 agent did not produce within anacceptable period of time of less than about 20 secs. an acceptableoil-in-water emulsion having an emulsion shear stability greater than orequal to 40 mins. because the estimated quantity in percent by weight ofDD compounds in the DD mixture having a molecular weight of 2434 to 4264is 16.4% by weight (which is less than at least 50% by weight) If thisestimated quantity in percent by weight is 50% by weight greater, anacceptable oil-in-water emulsion would be formed within an acceptableperiod of time. The 5/5/15 mixture of DD 20/DD 70/DD 150 in combinationwith 25% by weight of the NP 20 agent did not produce an acceptableoil-in-water emulsion because the estimated quantity in percent byweight of DD compounds in the 5/5/15 DD mixture having a molecularweight of 2434 to 4264 is 24% by weight (which is less than at least 50%by weight), and further because the weight average molecular weight ofthe mixture is 6281 (which is not between 2434 and 4264). If thisestimated quantity in percent by weight is 50% by weight or greater andif the weight average molecular weight is between 2434 and 4264, anacceptable oil-in-water emulsion would be formed within an acceptableperiod of time.

EXAMPLE XXXXIII

Repeat Example XXXXII where the percent by weight of the NP 20 agent inthe DD/NP 20 agent mixture is decreased to below about 60% by weight andthe percent by weight of the respective DD compounds (i.e. DD 20, DD 70,and DD 100) in the DD/NP 20 agent mixture is varied and/or adjustedaccordingly such that the weight average molecular weight of the DDmixture is 2434 and 4264, dispersity of the NP mixture is 1.0 to 5.0,and the estimated quantity in percent by weight of DD compounds in theDD mixture having a molecular weight between 2434 and 4264 is at least50% by weight, and find that an acceptable oil-in-water emulsion is notformed and/or is not formed within an acceptable period of time.

EXAMPLE XXXXIV

Repeat Example XXXXIII where the percent by weight of the NP 20 agent inthe DD/NP 20 agent mixture is increased above 85% by weight and findsimilar results.

EXAMPLE XXXXV

The emulsifying agent for this Example is the emulsifying agent ofExample XXXXII comprising the 5/15/5 mixture of DD 20/DD 70/DD 150 incombination with 75% by weight NP 20 agent. The emulsifying agent ismixed with an aqueous phase (e.g. brine) at a temperature of about 200°F. to form an emulsifying composition with the emulsifying agentcomprising from about 5% by weight to about 60% by weight of theemulsifying composition. From about 2,000 to about 60,000 gallons ofthis emulsifying composition at a temperature of about 200° F. isinjected into a heavy crude or tar sands formation via an injection orproduction well over a period of one to five days. The formation has atemperature of about 190° F. Subsequently, steam (75% to 100% quality)at 500° F. is injected into the formation for a period of 20 to 40 daysat a rate of 600 to 1,500 barrels per day. The production well isthereafter shut in for one to ten days to allow the steam andemulsifying composition to soak in the formation. Subsequently, theproduction well is opened up and production of oil-in-aqueous phaseemulsion is started with the assistance of a downhole pump at the bottomof the production well.

EXAMPLE XXXXVI

Repeat Example XXXXV but concurrently inject into the formation at arate of about 1,000 barrels per day the emulsifying composition with the500° F. steam such that the emulsifying composition enters into theformation at a temperature above P.I.T. (or about 210° F.) and theweight ratio of the 500° F. steam to the emulsifying composition isabout 20:1. The weight ratio of the steam to emulsifying composition canvary from about 1:1 to about 50:1, and hot water having a temperature of150° F. to 250° F. or hot water and steam can be substituted for thesteam in the same weight ratio. After shutting in the production wellfor a soak period of 10 to 20 days wherein the emulsifying compositioncools to below about P.I.T. (or about 210° F.) and oil-in-aqueous phaseemulsion forms, the production well is opened up and the oil-in-aqueousphase emulsion is produced having a greater or enhanced stability thanthe oil-in-aqueous phase emulsion of Example XXXXV.

While the present invention has been described herein with reference toparticular embodiments thereof and examples therefor, a latitude ofmodification, various changes and substitutions are intended in theforegoing disclosure and it will be appreciated that in some instancessome features of the invention will be employed without a correspondinguse of other features without departing from the scope of the inventionas set forth. For example, while mixing of hydrocarbon crude with theemulsifying composition has been described as taking place above thesurface of the earth, it is to be understood that mixing of hydrocarboncrude with the emulsifying composition below the surface of the earth,such as in a tubing of a producing well, is within the spirit and scopeof this invention. Similarly, while the production of an oil-in-wateremulsion has been described for purposes of transmission through apipeline, it is to be understood that the spirit and scope of thisinvention include the production of an oil-in-water emulsion for anysuitable purpose including, but not limited to, burning in aburner/boiler, and purposes of transmission through any pipe means.Thus, by way of example only, whenever "pipeline" is referred to in thespecification and the claims, it is to be construed to be any pipemeans, such as tubing of a producing well.

We claim:
 1. A process for recovering oil from a subterraneanhydrocarbon-bearing reservoir having a hydrocarbon and penetrated by awellbore, said process comprising the steps of:(a) injecting throughsaid wellbore and into said subterranean hydrocarbon-bearing reservoirhaving a hydrocarbon an emulsifying composition comprising an aqueousphase and a minor amount of an emulsifying agent such that theemulsifying composition contacts at least a portion of the hydrocarbonto form an oil-in-aqueous phase emulsion within said subterraneanhydrocarbon-bearing reservoir; and wherein said emulsifying agentcomprises a first agent having at least one first ethoxylatedalkylphenol compound and a second agent having at least one secondethoxylated alkylphenol compound, said at least one first ethoxylatedalkylphenol compound having a first general formula: ##STR27## whereinn₁ is an integer having a value of from about 7 to about 11, and y₁ isan integer having a value of from about 4 to about 200; and said atleast one first ethoxylated alkylphenol compound has a molecular weightdistribution with a dispersity of from about 1.0 to about 5.0 and with aweight average molecular weight of from about 558 to about 1582; andwherein at least about 50% by weight of said first agent comprises saidat least one first ethoxylated alkylphenol compound having a molecularweight of from about 558 to about 1582; and said at least one secondethoxylated alkylphenol compound having a second general formula##STR28## wherein n₂ is an integer having a value of from about 9 toabout 14, and y₂ is an integer having a value of from about 4 to about300; and said at least one second ethoxylated alkylphenol compound has amolecular weight distribution with a dispersity of from about 1.0 toabout 5.0 and with a weight average molecular weight of from about 2434to about 4264, and wherein at least about 50% by weight of said secondagent comprises said at least one second ethoxylated alkylphenolcompound having a molecular weight of from about 2434 to about 4264; (b)producing the formed oil-in-aqueous phase emulsion of step (a); and (c)recovering oil from the produced oil-in-aqueous phase emulsion of step(b).
 2. The process of claim 1 wherein said emulsifying agent comprisesat least one first ethoxylated alkylphenol compound having said firstgeneral formula wherein y₁ has a value greater than
 100. 3. The processof claim 2 wherein at least about 1% by weight of said emulsifying agentcomprises said first ethoxylated alkylphenol compound having said firstgeneral formula wherein y₁ has a value greater than
 100. 4. The processof claim 1 or 2 wherein said emulsifying agent comprises at least onesecond ethoxylated alkylphenol compound having said second generalformula wherein y₂ has a value greater than
 100. 5. The process of claim4 wherein at least about 1% by weight of said emulsifying agentcomprises said second ethoxylated alkylphenol compound having saidsecond general formula wherein y₂ has a value greater than
 100. 6. Theprocess of claim 1 or 2 wherein said emulsifying composition has atemperature of from about 35° F. to about the boiling point temperatureof the emulsifying composition.
 7. The process of claim 1 or 2 whereinat least about 70% by weight of said first agent comprises said at leastone first ethoxylated alkylphenol compound having a molecular weight offrom about 558 to about
 1582. 8. The process of claim 1 or 2 whereinsaid dispersity of said at least one first ethoxylated alkylphenolcompound is from about 1.0 to about 3.0 and said weight averagemolecular weight of said at least one first ethoxylated alkylphenolcompound has a value of from about 646 to about
 1582. 9. The process ofclaim 1 or 2 wherein at least about 70% by weight of said second agentcomprises said at least one second ethoxylated alkylphenol compoundhaving a molecular weight of from about 2434 to about
 4264. 10. Theprocess of claim 1 or 2 wherein said dispersity of said at least onesecond ethoxylated alkylphenol compound is from about 1.0 to about 3.0and said weight average molecular weight of said at least one secondethoxylated alkylphenol compound has a value of from about 2874 to about3824.
 11. The process of claim 1 wherein said emulsifying agentcomprises from about 60% by weight to about 85% by weight of the firstagent and from about 15% by weight to about 40% by weight of the secondagent.
 12. The process of claim 1 wherein said subterraneanhydrocarbon-bearing reservoir contains a residual quantity of saidhydrocarbon that did not form an oil-in-aqueous phase emulsion with saidemulsifying composition.
 13. The process of claim 1 wherein saidemulsifying composition is injected into the subterraneanhydrocarbon-bearing reservoir at a temperature above about 210° F. suchthat as the emulsifying composition cools below about 210° F., theemulsifying composition forms an oil-in-aqueous phase emulsion with thehydrocarbon having a greater stability than if the emulsifyingcomposition was injected into the subterranean hydrocarbon-bearingreservoir at a temperature below about 210° F.
 14. The process of claim1 additionally comprising subsequently injecting hot water and/or steaminto said subterranean hydrocarbon-bearing reservoir after injecting theemulsifying composition in order to push the emulsifying compositionfurther into the reservoir and to lower the viscosity of thehydrocarbon, causing the hydrocarbon to flow into contact with theemulsifying composition.
 15. The process of claim 1 additionallycomprising shutting in the wellbore for a soak period.
 16. The processof claim 1 additionally comprising injecting prior to step (a) acoemulsifying composition(s) into said subterranean hydrocarbon-bearingreservoir.
 17. The process of claim 1 wherein from about 1% by weight toabout 10% by weight of the emulsifying agent comprises said firstethoxylated alkylphenol compound having said first general formulawherein y₁ has a value greater than
 100. 18. The process of claim 1wherein from about 1% by weight to about 75% by weight of theemulsifying agent comprises the second ethoxylated alkylphenol compoundhaving said second general formula wherein y₂ has a value greater than100.
 19. The process of claim 1 wherein said oil-in-aqueous phaseemulsion is formed within about 20 seconds.
 20. The process of claim 1wherein said formed oil-in-aqueous phase emulsion has an emulsion shearstability of more than about 40 mins. when the emulsion shear stabilityof the formed oil-in-aqueous phase emulsion is measured with a rotorstator at 2,000 r.p.m. until the formed oil-in-aqueous phase emulsionfails.
 21. The process of claim 1 wherein said emulsifying compositionhas a temperature of from about 35 degrees F. to about the boiling pointtemperature of the emulsifying composition.
 22. The process of claim 1additionally comprising heating, prior to said injecting step (a), theemulsifying composition to a temperature above the phase inversiontemperature for the oil-in-aqueous phase emulsion.
 23. The process ofclaim 1 additionally comprising heating the emulsifying composition to atemperature above the phase inversion temperature for the oil-in-aqueousphase emulsion; and cooling the emulsifying composition to a temperaturebelow the phase inversion temperature of the oil-in-aqueous phaseemulsion such that the emulsifying composition forms an oil-in-aqueousphase emulsion with the hydrocarbon having a greater stability whencompared with an oil-in-aqueous phase emulsion formed with theemulsifying composition without having been initially heated to atemperature above the phase inversion temperature for the oil-in-aqueousphase emulsion and subsequently cooled to a temperature below the phaseinversion temperature for the oil-in-aqueous phase emulsion.
 24. Theprocess of claim 13 or 23 wherein said heating comprises accompanyingthe emulsifying composition with steam as the emulsifying composition isbeing injected into the subterranean hydrocarbon-bearing reservoir. 25.The process of claim 1 wherein said first ethoxylated alkylphenolcompound has the formula: ##STR29## and said second ethoxylatedalkylphenol compound has the formula: ##STR30##
 26. A process forforming a downhole emulsion in a wellbore extending into a subterraneanhydrocarbon-bearing reservoir and having a hollow tubing generallyconcentrically disposed with respect to a casing comprising the stepof:injecting an emulsifying composition(s) between the hollow tubing andthe casing in order to mix with fluids emanating from the subterraneanhydrocarbon-bearing reservoir and form an oil-in-aqueous phase emulsion,said emulsifying composition comprising an aqueous phase and a minoramount of an emulsifying agent such that when the emulsifyingcomposition contacts at least a portion of the fluids emanating fromsaid subterranean hydrocarbon-bearing reservoir, the oil-in-aqueousphase emulsion forms; and wherein said emulsifying agent comprises afirst agent having at least one first ethoxylated alkylphenol compoundand a second agent having at least one second ethoxylated alkylphenolcompound, said at least one first ethoxylated alkylphenol compoundhaving a first general formula: ##STR31## wherein n₁ is an integerhaving a value of from about 7 to about 11, and y₁ is an integer havinga value of from about 4 to about 200; and said at least one firstethoxylated alkylphenol compound has a molecular weight distributionwith a dispersity of from about 1.0 to about 5.0 and with a weightaverage molecular weight of from about 558 to about 1582; and wherein atleast about 50% by weight of said first agent comprises said at leastone first ethoxylated alkylphenol compound having a molecular weight offrom about 558 to about 1582; and said at least one second ethoxylatedalkylphenol compound having a second general formula: ##STR32## whereinn₂ is an integer having a value of from about 9 to about 14, and y₂ isan integer having a value of from about 4 to about 300; and said atleast one second ethoxylated alkylphenol compound has a molecular weightdistribution with a dispersity of from about 1.0 to about 5.0 and with aweight average molecular weight of from about 2434 to about 4264, andwherein at least about 50% by weight of said second agent comprises saidat least one second ethoxylated alkylphenol compound having a molecularweight of from about 2434 to about
 4264. 27. The process of claim 26wherein from about 1% by weight to about 10% by weight of theemulsifying agent comprises said first ethoxylated alkylphenol compoundhaving said first general formula wherein y₁ has a value greater than100.
 28. The process of claim 26 wherein from about 1% by weight toabout 75% by weight of the emulsifying agent comprises the secondethoxylated alkylphenol compound having said second general formulawherein y₂ has a value greater than
 100. 29. The process of claim 26wherein said oil-in-aqueous phase emulsion is formed within about 20seconds.
 30. The process of claim 26 wherein said formed oil-in-aqueousphase emulsion has an emulsion shear stability of more than about 40mins. when the emulsion shear stability of the formed oil-in-aqueousphase emulsion is measured with a rotor stator at 2,000 r.p.m. until theformed oil-in-aqueous phase emulsion fails.
 31. The process of claim 26wherein said emulsifying composition has a temperature of from about 35degrees F. to about the boiling point temperature of the emulsifyingcomposition.
 32. The process of claim 26 additionally comprisingheating, prior to said injecting, the emulsifying composition to atemperature above the phase inversion temperature for the oil-in-aqueousphase emulsion.
 33. The process of claim 26 additionally comprisingheating the emulsifying composition to a temperature above the phaseinversion temperature for the oil-in-aqueous phase emulsion; and coolingthe emulsifying composition to a temperature below the phase inversiontemperature of the oil-in-aqueous phase emulsion such that theemulsifying composition forms an oil-in-aqueous phase emulsion with thehydrocarbon having a greater stability when compared with anoil-in-aqueous phase emulsion formed with the emulsifying compositionwithout having been initially for the oil-in-aqueous phase emulsion andsubsequently cooled to a temperature below the phase inversiontemperature for the oil-in-aqueous phase emulsion.
 34. The process ofclaim 26 wherein said first ethoxylated alkylphenol compound has theformula: ##STR33## and said second ethoxylated alkylphenol compound hasthe formula: ##STR34##
 35. A process for forming a downhole emulsion ina wellbore extending into a subterranean hydrocarbon-bearing reservoirand having a hollow tubing generally concentrically disposed withrespect to a casing comprising the step of:injecting an emulsifyingcomposition through a hollow sucker rod similarly disposed in saidhollow tubing, and through a by-pass conduit communicating with thehollow tubing in order to mix with fluids emanating from thesubterranean hydrocarbon-bearing reservoir and form an oil-in-aqueousphase emulsion, said emulsifying composition comprising an aqueous phaseand a minor amount of an emulsifying agent such that when theemulsifying composition contacts at least a portion of the fluidsemanating from said subterranean hydrocarbon-bearing reservoir, theoil-in-aqueous phase emulsion forms; and wherein said emulsifying agentcomprises a first agent having at least one first ethoxylatedalkylphenol compound and a second agent having at least one secondethoxylated alkylphenol compound, said at least one first ethoxylatedalkylphenol compound having a first general formula: ##STR35## whereinn₁ is an integer having a value of from about 7 to about 11, and y₁ isan integer having a value of from about 4 to about 200; and said atleast one first ethoxylated alkylphenol compound has a molecular weightdistribution with a dispersity of from about 1.0 to about 5.0 and with aweight average molecular weight of from about 558 to about 1582; andwherein at least about 50% by weight of said first agent comprises saidat least one first ethoxylated alkylphenol compound having a molecularweight of from about 558 to about 1582; and said at least one secondethoxylated alkylphenol compound having a second general formula:##STR36## wherein n₂ is an integer having a value of from about 9 toabout 14, and y₂ is an integer having a value of from about 4 to about300; and said at least one second ethoxylated alkylphenol compound has amolecular weight distribution with a dispersity of from about 1.0 toabout 5.0 and with a weight average molecular weight of from about 2434to about 4264, and wherein at least about 50% by weight of said secondagent comprises said at least one second ethoxylated alkylphenolcompound having a molecular weight of from about 2434 to about
 4264. 36.The process of claim 35 wherein from about 1% by weight to about 10% byweight of the emulsifying agent comprises said first ethoxylatedalkylphenol compound having said first general formula wherein y₁ has avalue greater than
 100. 37. The process of claim 35 wherein from about1% by weight to about 75% by weight of the emulsifying agent comprisesthe second ethoxylated alkylphenol compound having said second generalformula wherein y₂ has a value greater than
 100. 38. The process ofclaim 35 wherein said oil-in-aqueous phase emulsion is formed withinabout 20 seconds.
 39. The process of claim 35 wherein said formedoil-in-aqueous phase emulsion has an emulsion shear stability of morethan about 40 mins. when the emulsion shear stability of the formedoil-in-aqueous phase emulsion is measured with a rotor stator at 2,000r.p.m. until the formed oil-in-aqueous phase emulsion fails.
 40. Theprocess of claim 35 wherein said emulsifying composition has atemperature of from about 35 degrees F. to about the boiling pointtemperature of the emulsifying compositions.
 41. The process of claim 35additionally comprising heating, prior to said injecting, theemulsifying composition to a temperature above the phase inversiontemperature for the oil-in-aqueous phase emulsion.
 42. The process ofclaim 35 additionally heating the emulsifying composition to atemperature above the phase inversion temperature for the oil-in-phaseemulsion; and cooling the emulsifying composition to a temperature belowthe phase inversion temperature of the oil-in-aqueous phase emulsionsuch that the emulsifying composition forms an oil-in-aqueous phaseemulsion with the hydrocarbon having a greater stability when comparedwith an oil-in-aqueous phase emulsion formed with the emulsifyingcomposition without having been initially heated to a temperature abovethe phase inversion temperature for the oil-in-aqueous phase emulsionand subsequently cooled to a temperature below the phase inversiontemperature for the oil-in-aqueous phase emulsion.
 43. The process ofclaim 33 or 41 or 42 wherein said first ethoxylated alkylphenol compoundhas the formula ##STR37## and said second ethoxylated alkylphenolcompound has the formula: ##STR38##
 44. The process of claim 35 whereinsaid first ethoxylated alkylphenol compound has the formula: ##STR39##and said second ethoxylated alkylphenol compound has the formula:##STR40##
 45. A process for recovering oil from a subterraneanhydrocarbon-bearing reservoir having a hydrocarbon and penetrated by awellbore, said process comprising the steps of:(a) injecting throughsaid wellbore and into said subterranean hydrocarbon-bearing reservoirhaving a hydrocarbon an emulsifying composition comprising an aqueousphase and a minor amount of an emulsifying agent such that theemulsifying composition contacts at least a portion of the hydrocarbonto form an oil-in-aqueous emulsion within said subterraneanhydrocarbon-bearing reservoir; wherein said emulsifying composition isinjected into the subterranean hydrocarbon-bearing reservoir at atemperature above about 210° F. such that as the emulsifying compositioncools below about 210° F., the emulsifying composition forms anoil-in-aqueous phase emulsion with the hydrocarbon having a greaterstability than if the emulsifying composition was injected in to thesubterranean hydrocarbon-bearing reservoir at a temperature below about210° F.; and wherein said emulsifying agent comprises a first agenthaving at least one first ethoxylated alkylphenol compound and a secondagent having at least one second ethoxylated alkylphenol compound, saidat least one first ethoxylated alkylphenol compound having a firstgeneral formula: ##STR41## wherein n₁ is an integer having a value offrom about 7 to about 11, and y₁ is an integer having a value of fromabout 4 to about 200; and said at least one first ethoxylatedalkylphenol compound has a molecular weight distribution with adispersity of from about 1.0 to about 5.0 and with a weight averagemolecular weight of from about 558 to about 1582; and wherein at leastabout 50% by weight of said first agent comprises said at least onefirst ethoxylated alkylphenol compound having a molecular weight of fromabout 558 to about 1582; and said at least one second ethoxylatedalkylphenol compound having a second general formula: ##STR42## whereinn₂ is an integer having a value of from about 9 to about 14, and y₂ isan integer having a value of from about 4 to about 300; and said atleast one second ethoxylated alkylphenol compound has a molecular weightdistribution with a dispersity of from about 1.0 to about 5.0 and with aweight average molecular weight of from about 2434 to about 4264, andwherein at least about 50% by weight of said second agent comprises saidat least one second ethoxylated alkylphenol compound having a molecularweight of from about 2434 to about 4264; and (b) recovering oil from theformed oil-in-aqueous phase emulsion of step (a).